Another nod for the Dell Mini-10. I bought it with Ubuntu preinstalled, but wound up swapping Netbook Remix for a plain install of Karmic. With Google Chrome running fullscreen, it's a very usable and capable web browsing machine, but I echo Steve's comments about trying to do any real coding on it.
6-Cell battery is worth it, the keyboard is well laid-out and decently large, and I went with the 32 Gig SSD so I don't have to worry about bumping it during operation. It's a bit unnerving hitting the power button waiting for the comforting hum of starting up, as the whole system is passively cooled and makes zero noise.
My main gripe is that it's near impossible to click and drag on the small touchpad with the integrated button.