Some hackers over at HackaDay.com have worked some magic on a Zipit, a small wireless messenger that looks a lot like a tiny netbook. They've got tutorials on how to flash the 2.8″ device to add a Linux kernel, mouse functionality, audio and many more mods.
Their claim? "With Zipit, who needs a netbook?" I'm not totally sure the answer is 'nobody', but the article in question may hold interest for you regardless.