I don't have one, I only almost got one. I want to emphasize what netcrasher said:
Plus on the portability and pricing, and in the case of the HP Mini, the keyboard is amazingly comfortable for typers.
Minus on the dependability and quality of construction.
To be fair, netbook are an odd success from the original intent of the OLPC project. (One Laptop Per Child.) A lot of people are picking it up for basic casual use. It's great if the cons don't dissuade you.
A particularly promising variant is one that is outfitted with a broadband cellular card. I say this because, if you are someone who travels a lot, and is not always at a hotspot, having cellular broadband can be a godsend. Not only that, but because they are typically so affordable, yet portable, they become good travel companions where you won't sweat too much if they somehow got damaged or stolen.
Ah, but I didn't fit the profile of someone who needed that, so that's why I ultimately did not buy one, despite the relatively low price....
The future of netbook looks very bright indeed. Intel's
Moblin project is very interesting. Aimed at providing a great user experience and interface specifically with netbooks in mind, most people may not even know or care that it's actually Linux.
Another variety of netbook Linux is
Splashtop, which I am actually running through my desktop PC. Splashtop is wild because, it's actually Linux that is embedded into the computer's firmware. Boot up is
extremely fast, and you technically don't even have to have a hard drive to make such a computer run. This is a big deal in that netbooks can tend to be kind of slow given the relatively low components used.
Splashtop should be available with the Lenovo S10 series, but you will most likely have to manually install it first before you can use it....
Anyway, I agree that, if you can, to pay a little extra for the bigger 10" screens. It's one of those things that you'll be staring at all day long, and while the increased price encroaches into the normal laptop territory, I think it's worth paying basically $50 extra for a decrease in eye strain.
But again, I didn't buy one. Instead, an overstocked 12" Lenovo with better construction and features for $400 suited me better, so that's what I have instead....