I recently purchased a Samsung NC10 netbook. I chose the Samsung because my main computer is a Macbook Pro and of the handful of netbooks out there this seemed a good candidate for turning into a hackintosh (running OSX on it).
I decided that ideally I would keep the XP functionality just in case, so I am currently dual-booting it with XP/OSX. It took a little messing with to get OSX working fully, but it now works nicely. It is possible to get the in-built wireless card working, but it is a very messy process and the general consensus is just to swap it out with a cheap airport-compatible card, which I did.
The machine itself is really nice. It is a little heavier than some, but that is mainly due to the 6-cell battery it has, over the 3-cell batteries most of its competitors have. This gives the machine around 5-6 hours battery life in XP and 4-5 hours in OSX (the power management in XP is slightly better).
The keyboard is a major selling-point. It is very big in terms of netbook keyboards, over 90% of a full-size keyboard. This means that while it is not easy to touch-type, you can at least type reasonably fast and are less susceptible to mis-keying.
Speed-wise this little machine is pretty good. Boot times are very quick indeed and navigating either operating system seems pretty slick. Obviously this is no gaming platform, and you would not want to render a video on it (the Intel Atom processor is designed for battery life, not performance) but for what it is intended for it is a great little machine.
The OSX functionality is not perfect. I used the instructions from Mysticus C to get it working. It is fairly straight forward actually, once you understand how it works.
Aside from needing to swap out the wireless card the sound drivers are not perfect. There are some hacked ones out there that enable sound, but the in-built microphone is still not fully supported. Hopefully in coming weeks there will be a driver available to support this. The webcam is already supported, so once the mic is working this will be a great little video conf machine. Bluetooth works well, as does the trackpad (complete with multi-touch!).
I intend to end up with a triple-boot system by putting Windows 7 on there too, but the bootloader is slightly different so I need to work out if it will be straight forward or not. My main partition is FAT32, so all the operating systems can access it. I may at some point replace this with NTFS (there is an OSX driver to support it) but I am not sure that will be necessary.
I have only been using the NC10 for a short while, so I will post again once I have got used to it. For now I am very happy with it!