I just got a bluetooth keyboard for my iPad, and I have to say it makes the iPad much more functional as a laptop replacement. Its rather generically named the Logitech Tablet Keyboard for iPad
Here are some specific limitations.
— There are no keyboard shortcuts for doing things. For example, in mail there is no way to do new message (at least that Ive found). Likewise there is no way to send. I can start typing a persons name and I will get a list of possible completions. There is no way to say yes, thats the one, without touching the screen—even if there is only one possible completion.
— Things like Cmd-Tab ought to bring up the running apps, like double-tapping the home button does. Interestingly, double-tapping the home button on the bluetooth keyboard works the same as double-tapping the home button on the device. But, there is no keyboard based navigation (e.g., arrow keys dont do anything.)
— This keyboard has a magnifying glass key that jumps you to the search feature. I like that, but then I type a search term like word (to find wordpress) and Im back to no navigation. I can see wordpress in my search results but I have no way to get my cursor down from the searching box into the results and then hit enter to activate wordpress.
On the plus side, it acts very much like a real keyboard on a real workstation. For example, Ive just bought a US-layout keyboard and Ive hooked it up to my UK-localised iPad
Also on the plus side, iOS seems to realise that I have an external keyboard, so it doesnt take up half the screen with a visual one. I can bring up the visual keyboard on the screen if I want to (doesnt make much sense), but its smart in that regard.
The particular keyboard I got also comes with a case that turns into a stand. I like that stand quite a bit, because I have bought an after-market sleeve for my iPad. My sleeve (from TeckNet) is a fair bit thicker than the usual Apple cover (and it cost £10 instead of £60). The stand from the keyboard works well, though.
Im interested to see how well this will hold up on a train, where it is quite bumpy. Sitting on a table, its brilliant.