A friend had a netbook with Ubuntu Netbook Remix. It looked like a nice OS that simplified the netbook experience.
When I finally bough my own netbook I was more or less convinced that I would throw out the existing operative system and install Linux on it. However I have not felt the need to do so. My notebook is fast enough to run Windows XP Home. With the hibernate mode the netbook is relatively fast to boot/start. In the end I don't feel like going through the hassle of reinstalling anything.
If the it had come pre-installed with Linux my feeling is that I would have kept that OS.