Archos 605 WiFi
Archos is a fine piece of mediaplayer, which runs on a customized linux kernel.
Perfect for use, when you don't want to waste time booting up your lap top on the subway, bus, airplane or whatever transportation you are on. Right now, I use it for study reasons. Very nice to have all loads of books in PDF format, and with the 4.3 inch screen, the reading is a breeze.
The Opera web browser used by Archos is fast and almost flawless. Easy to use and with loads of nice features, such as zoom capabilities, flash and several script languages. Works great on YouTube, as long as you have the neccessary bandwith. Archos has released a SDK, which you cand download from their site, if you are up to writing new appz.