Like Conan the Librarian, I have just bought a dell axim 51v and I'm really pleased with it. They are still running a special offer I think. It fits nicely into my pocket, it has wifi & bluetooth. I've got msn messenger & skype running on it so when your away communication home is easy.
Its got a CF card slot to I can view my photos off my digital slr.
You will need the extended battery though, however i've just bought one off ebay for around £8 so you can fill your pockets up with those.
It's brilliant