HP iPaq - Wireless (11g) Internet, Bluetooth for my GPS receiver, SD card slot. I highly recommend mine (H4150) but it's probably out of date already! I use it at home to browse the Pelican forums when I can't be bothered firing up my P4. When I'm out of the office, it's good fun finding wireless hot-spots and logging into MSN, checking email or browsing the Pelican forums...
There's a local cafe near my home, where you can sit and drink coffee, while using their wireless. It's pretty neat.
[edit] Good battery life, nice screen res. I crunch DVDs to fit on my SD cards (4 feature movies per 1gb card) and they play flawlessly. I also have a ton of MP3s on it. My GPS receiver, together with mapping and navigation software I bought gives me a full voice-command Navigation System, which is handy in the car.