I've had one for a year now and it is brilliant. The one downside is the battery life but as long as you charge it daily it is fine. The apps on it are superb, a lot are free or a token amount of 59p. It runs absolutely everything for me, synchronises with my company exchange server and picks up emails, my diary that my planner updates, my 5 other email accounts. I have sat nav on there, live trains when I go into London and lots more.
The whole family have them. :roundgrin you can surf the net, keep in touch on msn, facebook and even remote into your pc. You get unlimited data with them so it is always live. I don't use it as a phone much
My daughter has one she thinks it is brilliant, she does everything on it, you can even use it to phone people:roundgrin I am able to get on the computor more now as she uses that instead of the computor.
I am amazed at how good it is even getting on the internet is quick, but as Martyn says the battery life is not so good you have to keep charging it.