The keys aren't necessarily larger than those on a tablet's touch screen. But they have real buttons that you press to help you hit the right key. Testers found that most of the keyboards have pros and cons. The Menotek is lightweight and can even be rolled up. But its small, soft keys are hard to use, and it's easy to make mistakes.
The RocketFish and Belkin keyboards have convenient tablet-specific buttons, like Home and Lock Screen. And they have shortcuts to do tasks like running a slideshow. The RocketFish keyboard also serves as a case and a stand. But at more than 2 pounds, it's pretty heavy. And the Belkin case is so snug, it's hard to get even the thinner iPad2 in and out of it.
A better option is the ZAGGfolio keyboard for $100. It's not quite as snug a fit, and it has a versatile keyboard and handy iPad-specific buttons and shortcuts.
But if you really want full-sized keys, try Apple's Wireless Keyboard. At $70, it costs less than the others tested, but you'll need to pay extra for a stand and case.
Consumer Reports also tested keyboards for Android tablets like the Samsung Galaxy Tab. The $70 Logitech keyboard is a good choice. It's lightweight and has full-sized keys and customized tablet controls.