I bought the Toshiba NB205 2 weeks ago.
Terrific little machine with awesome battery life. Plus one of the USB ports is a charging port that will charge your USB device even when the computer is off.
I do a good deal of flying so I wanted something less cumbersome than a laptop but with enough juice to watch a full movie without conking out.
On my first trip. I watched a 2 hour movie and 2 TV shows on it. Still had over 60% battery life left (it's rated for 9.5 hours). I have ran it for 7 hours and still had 30% battery.
The main thing about the netbooks is keyboard, keyboard, and the keyboard. Did I mention to try the keyboard?
Most all have the same basic specs (1.66 Atom 280 CPU, 160GB HDD, 1GB Ram, Intel integrated graphics) so pick one you can type on without making too many errors.
The Toshiba has a great keyboard and a real touchpad with 2 real buttons that are located where they should be. These 2 things (plus the great battery life) are what made me get the Toshiba.
If you get one now, it will likely come with Windows 7 starter. I went ahead and got mine with XP since I wasn't sure that all my work applications would play nice with 7.