I just bought an MSI Wind laptop/netbook and so far I love it. It's tiny, weighing in 2.2 pounds. This includes the bigger, 6 cell battery that provides 6 hours of use. I haven't had a chance to push that envelope yet, but it's on my list of things to do. :)
Here's a picture of it sitting on my 15" MacBook Pro (link). It literally makes the sleek MBP look clunky. It feels that way too. 2.2 versus 5.5 pounds.
The most surprising thing about the Wind is that it's got a hyperthreaded CPU. (Traditionally ultra small notebooks had a single CPU and were slow). It's got the Intel Atom CPU, but with hyperthreading, so it's amazingly responsive. My model came with 1 gig of memory (I've already upgraded it to 2) and a 160 gig hard drive. The external monitor drives my 19" widescreen nicely. So far I can't tell that it's any slower than my MacBook Pro for almost everything.
The keyboard's alphanumberics are fine to use, but the "edge keys", like CTRL and ? are odd