I bought one in December 2009. I paid [...] for a manufacturer reconditioned example on [...]; since when, the price has gone up.
It came with SLED10 Linux, which I found to be dreadful. It was impossible to configure or add software, so, using an external CDROM, I installed Ubuntu 9.10 Linux which was free and simple to use.
With a few tweaks it was running perfectly well, and by now I am up to Ubuntu (Linux) 10.10.
The 2 GB memory card cost me £30 last week, because I wanted to use it for development work, and I needed to tweak a file in Linux to get the VGA port to work with an external monitor.
I wouldn't put windows on this, because it is practically bound to be on a disk and costs a lot of money. Also if anything goes wrong with windows, you're stuck with it unless you re-install, and that may be limited by licensing. For example, there are no legal XP disks to be had.
Linux is free, and mine boots in under 30 seconds.
The screen is fabulously detailed, but not in direct Sunlight. The speakers are very crisp and relatively large, much larger than on a standard laptop for example, and it will happily play music all day, especially since the disk is 120GB.(Obviously on mains power).
Originally the Ubuntu Linux couldn't run Skype as the microphone caused the soundcard to crash, but in 10.10 it is fully operational at last, due to the VIA chipset being fully ported.
It gets warm, so use it on a hard surface to allow it to breathe underneath. Having said which, it has never shut down on me due to overheating.
Excellent.