What is it about April Fools' Day jokes that we love so much? Perhaps it's that, in the midst of the crushing influx of information that many of us cope with daily, a well-constructed prank provides a welcome break. For a moment, we smile, even when the joke is a tried-and-true chestnut.

Google has a strong tradition of sublime hilarity each April 1. Last year, the company announced two faux products designed to elicit a chuckle from unsuspecting (and suspecting) readers: Gmail Paper (6GB of messages, rendered as hard copy) and Google TiSP, a plumbing-based Internet Service Provider dedicated to harnessing the underutilised potential of the world's 'dark porcelain'.

In recent times, many other sites have pulled our collective leg with April Fools pages marked by realistic graphics and ridiculous but deadpan copy. Here are ten of our favourites.

10. Facebook Funnies
Last year, Facebook users noticed some unusual entries scattered among News Feed updates, including the announcement of a new LivePoke feature, in which invited users to dispatch a real live person to physically poke their Facebook friends (offer limited to first 100 members of a network). Another entry reported that Harry Potter and Voldemort (more of a MySpace kind of guy anyway) had returned to their former relationship status as mortal enemies. Good work, guys, and better luck next year on moving up our list.

9. Dead Fairy on eBay
In late March 2007, Dan Baines posted a web page describing (and illustrating with detailed photos) the discovery of what appeared to be the remains of a "real" fairy. Baines claimed that the mummified fairy corpse was recovered along an old Roman road in Derbyshire, England, by a dog-walker who preferred to remain anonymous. The bones of its diminutive, human-like skeleton were hollow, like a bird's, making it "particularly light", an anatomical peculiarity whose contribution to airworthiness was enhanced by the body's extremely leaflike uh, lifelike wings.

Over the next several days Baines, a magician and prop-maker, received hundreds of messages from credulous and (and in some instances worried) fairy-loving readers. To put their minds at ease, he revealed the hoax. Eventually Baines sold his creation on eBayfor £280.

8. PodShave and PodShaveLady
Sometimes, a prank's premise is so plausible that you have to ask yourself: "Why isn't there a product like that?" When iLounge posted breaking news of a new video-playing iPod V from Apple on March 31, 2004, no one took the bait. The real video iPod, which was just around the corner, made too much sense for the iPod V prank to be funny.
But wags at the now-defunct PodGear.net had more success with their electric-razor attachments for iPod Classic or Mini. Several Apple news sites, posted tongue-in-cheek reviews of these ersatz iPod accessories, leaving many wondering, "Does my back hair need grooming and can I dance to it?"

7. Wikipedia Brittanica
If we can believe Wikipedia's own Wiki page on the subject (at first unqualified, but subsequently clearly labelled as a joke), the popular user-created reference site was nearly absorbed by venerable dead-tree competitor Encyclopedia Britannica on April 1, 2005. Despite the promise of handsome severance packages for the founders of what was slated to become known as Wikimædia, the deal likely fell through, perhaps due to the onerous financial burden it would have placed on contributors to the newly merged publications. Though future costs were estimated at an astronomical £99.97 for each page creation or edit, the new Wikipædia promised to offset them by offering contributors a chance to win a rare photo of Margaret Thatcher from her days on the burlesque circuit.

6. Water on Mars
NASA's Astronomy Picture of the Day tends to be a beautiful high-resolution image of a far-off nebula, one of the moons of Saturn, or perhaps a comet streaking through the heavens. But the most startlingly unexpected image in the Astronomy Picture of the Day archive may be a photograph dated April 1, 2005, that conclusively established the presence of water on Mars.
In other space-related news, alert readers of the ordinarily factual Space Daily news site were surprised to learn on the same day that President Bush had cancelled the Space Shuttle programme.

5. Animated Tattoos
It was only a matter of time before someone achieved a technological breakthrough to lift body art above its humble drunken-sailor beginnings. That breakthrough was announced and documented on April 1, 2006, when the trusted HowStuffWorks website revealed the secret behind the animated tattoo - the Programmable Subcutaneous Visible Implant (PSVI). Buoyed by the article's success, HowStuffWorks followed it up last April with another behind-the-scenes look at tech implantation: How Cell-Phone Implants Work.

4. Indescribably Geek-elicious
ThinkGeek, the web-based retailer of 'Stuff for Smart Masses', usually observes April Fool's Day by posting new products that not only serve as a catalyst for mirth, but often defy the laws of physics. Starting in 2002 with the Desktop Zero-Point Power Generator , which converted abundant and "naturally occurring" electromagnetic energy into 120-volt AC power ("less than 600 rem of residual ionising radiation!").

ThinkGeek went on to offer CaffeDerm caffeine-delivering dermal patches (reminiscent of Nicarest smokable nicotine sticks, reported in the Onion back in 1998); Buzzaire caffeine inhaler ; a PC EZ-Bake Oven (fits in a 5¼-inch drive bay); wireless extension cords; the vinyl-ripping, 2-terabyte, 33-pound iZilla Media Monster digital media player; and a USB desktop tanning centre.

But latter-day Edisons at ThinkGeek outdid themselves with the Screened Sphorb, a device so unbelievably awesome that its accompanying QuickTime video - to say nothing of the attendant text description - don't begin to capture its multifaceted brilliance. What self-respecting geek could pass up a product that lets you "mod elementals AND screen drive in twice the time using only half of the optional memory pods, while the other half waits to achieve a normalized state" for a mere $39.99 (£20)? Best of all, legacy Sphorbs are fully engaged in the emulation process! Caveat emptor: no matter what assurances ThinkGeek's Screened Sphorb page makes about availability, the item may remain on back order indefinitely (or infinitely).

3. Beyond Buggy
Usually, the moderated posts on the Forum on Risks to the Public in Computers and Related Systems (a.k.a. Risks) focus soberly on news about security flaws in computer programs, and the life-threatening unintended consequences of those programs. But around the first of April each year, Risks takes a decidedly silly turn, featuring satirical, sometimes macabre, and possibly fictitious reports of technology gone wrong.
Examples from the April 1, 2006 issue include reports about a motorist trapped in a traffic circle for 14 hours by his car's malfunctioning lane-keeping software; and about the announcement at Cambridge University of new full-scale mapping software (where 1km of the real world is represented by 1km of the map) that had revealed errors in the location of actual roads and buildings. (Spokesperson Lewis Carroll assured reporters that the maps would be annotated to reflect the real-world errors.)

Then there was a post about the "successful" evacuation of an Airbus 380 in 90 seconds. The latter quotes a statistics-enamoured Airbus source, who downplayed reports of injuries during the record- (and femur-) breaking deplaning: "In a group of 853 people, the chances that one person has a broken leg and doesn't yet know it are substantial. The test showed that everyone came out at least as healthy as when they went in."

2. Opera SoundWave
The web-browser business is highly competitive, and developers like Mozilla, Microsoft, and Opera are always trying to outdo each other with breakthrough enhancements. So it seemed like business as usual when, on April 1, 2005, Opera issued a press release announcing Opera SoundWave, described as an exciting platform-independent real-time technology for short- and medium-range interpersonal communication.

The company stated that it had accidentally discovered SoundWave during an R&D study to speech-enable Opera's email client, and included a link to a demo of the analog-signal-processing technology.

We hoped that continued healthy competition in the browser market would prompt further advances in web-enabled communications, but Opera's ill-advised 2006 venture into stock photography was a disappointing follow-up.

1. Deer in camouflage
On April 1, 2007, People for the Ethical Treatment of Animals' (PETA) blog, The PETA Files (say it out loud), contained a brief entry regarding a new Minnesota-based anti-hunting group called Hunting Is Downright Evil (HIDE), which had developed an ingenious new plan to protect local deer from hunters, first tranquilising them (the deer, not the hunters), then painting them with a camouflage pattern, and finally re-releasing them into the wild. It certainly gave a new twist to the term 'deerhide'.

Despite the telltale date right next to the blog post's title, dozens of commentators blasted away at HIDE, PETA, and each other until sunset. Only at 5:44pm on April 1, after a score of vitriolic denunciations of deer painting, hunt interference, and "tree-huggin' idiots", did a lone voice finally interject: "Y'all know what day it is, right?"

Needless to say, most subsequent commentators persisted in not getting it. PETA was no newcomer to the art of the prank, either: In 2000, the organisation announced plans to sabotage a Texas bass fishing tournament by knocking fish out with tranquilisers. It's a joke, son.