Recently, I've acquired a netbook. In particular, I got an HP Mini (I got one with a solid state drive, but the one linked looks like a really good deal). I love it. It is small and light enough (about 2 lbs.) that I can toss it into my bag with my gaming books and not notice the weight. The keyboard on this thing doesn't have tiny keys. The screen is small, yes, but at 10" it isn't too tiny, and the processor has more than enough power for running anything I'm likely to do on it. It is a great little machine. At less than $400, it was a great buy.
It is definitely small enough to use at the gaming table without it getting in the way. It doesn't even have the 'wall' effect that a larger notebook PC would have.
The question? What can I use it for?
So far, as a player, I've been keeping my character sheets on it. I've bookmarked some Wikipedia (and similar) pages of interest to my characters (things that they are more knowledgeable about than I). I've bookmarked important pages on d20srd.org.
As a GM, I've also been using it to collect pictures and such - visuals to show the players.
Any other ideas?