This week I bought a Dell Mini 10v on eBay (GBP 150, shipping included). I wanted a cheap, light and noiseless device to write code while I'm away from my desktop computer. With the Dell Mini 10v I got all those features, so I'm quite happy with it.
Being a 10" machine, it's not so portable as the Mini 9 which is now playing my music on the living room, but that extra inch gives you a perfectly usable keyboard.
I'm running Ubuntu 10.10 on it -- the regular desktop edition, not the Netbook Remix. XMonad works great with these kind of machines where screen real state is so scarce, as usual. Its Atom N270 is powerful enough for working on my experiments in Python, Haskell and Common Lisp. I'll give it a try with Eclipse and Java later, but I'm afraid it might be just barely usable, if at all.
I had to install the proprietary Broadcomm drivers in order to have a working WiFi :-( Since I don't run the default GNOME desktop environment, I replaced the NetworkManager application with ConnMan, which gives me a CLI interface to connect to wireless networks.
Battery life's rather low, though: Just two and a half hours when reading Practical Common Lisp and working through the code with Emacs and SBCL. Most probably I'll get a 6-cell replacement battery, available on eBay for GBP 35.