Apple’s iPhoto is a powerful tool on its own, but it can do even more with the right plug-ins. Here are six iPhoto ’11 – compatible plug-ins to get you started.

Add high-quality watermarks

Blue Crowbar’s Impression plug-in (£6.99 Mac App Store; www.bluecrowbar.com) gives iPhoto users a simple way to add a precreated watermark to batches of photos. When you export a watermarked photo, Impression reimports it into iPhoto – a feature that can be helpful if you’re working exclusively in iPhoto or you plan on re-exporting the images later. One problem with the plug-in is that the controls are placed on top of the photo, which makes it hard to see the watermark until you take your cursor off the photo and the controls disappear.

Destroy duplicate photos

Many iPhoto users find themselves with multiple copies of the same photo, and deleting them manually can take eons. The Duplicate Annihilator ($8 [£5]; www.brattoo.com), from Brattoo Propaganda Software, is a great plug-in for deleting copies of photos fast. It goes through your library and uses a variety of algorithms to detect duplicate images, but it also spots similar photos that have minor differences. It can delete duplicates immediately upon detection or mark them with keywords so you can sort through them yourself later. The result is a less-cluttered, faster, and happier iPhoto library.

Upload to Picasa

iPhoto ’11 has built-in sharing support for Facebook and Flickr, but not Google’s Picasa service. With Picasa’s iPhoto plug-in (free; www.picasa.com), you can upload images to your Picasa galleries. When you export your selected photos in iPhoto, the plug-in will give you the option to put them directly in a new or previously created album. Still, Picasa addicts may prefer using the standalone Picasa application in addition to or instead of iPhoto.

Share large photos with YouSendIt

Share files that are too big for an email with YouSendIt’s iPhoto plug-in (free; www.yousendit.com). The plug-in lets you send files up to 2GB in size for free (you’ll need to sign up for a free YouSendIt account). You can choose your file type and size during the export, and you can send personalised messages along with the file. You can send only one file at a time for free, but for a monthly fee you can also send large groups of photos via the plug-in.

Add borders, text, and watermarks

Send large projects to the web or a printer, complete with custom borders, copyright information, and watermarks. This easy-to-use plug-in from Border FX (donation requested; www.iborderfx.com) has a simple interface for batch border, text, and watermark additions. You can control border sizes and ratios, stroke thickness, and drop shadows, as well as add blur and desaturated borders. You can add text to each photo individually or to batches of images. The watermark tool lets you use your own logo or image and has a variety of customisation options. The best part about this plug-in is that you can save presets so you can apply them to future images – ideal for photographers who want a uniform look for all their photos.

Manage your libraries

OK, this one is a standalone app not a plug-in, but it is an incredibly useful tool for iPhoto users.

Normally, you only have one iPhoto library for all of your photos. You then navigate that library through albums, events, and keywords. This single-library system can slow down iPhoto and get a little messy when you have thousands of photos from years of parties, birthdays, and holidays. iPhoto Buddy’s (free, www.iphotobuddy.com) solution is to create multiple libraries and manage them outside of iPhoto. You can create a new iPhoto library and see details about existing libraries – all without opening iPhoto. Double-click on a library within iPhoto Buddy to open it up in iPhoto.