With the iPad 2 set to go on sale on Friday, you may be wondering whether to spend the extra £100 to get an an iPad 2 with 3G?

Many smartphones – including the iPhone 4 with its new Personal Hotspot feature – let you share their internet connections with other devices. For example, if you are signed up for Three’s ‘The One Plan’ (£25) you get access to Data Tethering at no extra cost, including unlimited data.

Creating a Personal Hotspot with your iPhone could save you money compared to the iPad 3G plans, plus you won’t have to pay extra upfront for the 3G iPad.

On the other hand, if you spend the extra £100 for a 3G model, there’s no contract to sign and you’re not required to buy a data plan – so the extra cost of the 3G iPad might not be too much to spend if you want to keep your options open.

One final wrinkle to the 3G buying decision: only 3G iPad models come with GPS capabilities. There’s a good reason for this – iOS devices use something called assisted GPS to dramatically decrease the amount of time it takes for the devices to determine their location. In any event, if you dream of using your iPad as a jumbo GPS navigation console, you’ll absolutely need a 3G model.

The following tables will help you compare the current pricing plans for Personal Hotspot on the iPhone and the monthly cost to run a 3G iPad.