I bought the ASUS eee PC1000 and put in:
2Gb of RAM (Needed for W7).
A 64Gb fast Runcore SSD.
Windows 7 (and disable the pagefile to reduce read/writes).
All works swimmingly, I get 5 hours of watching video on it (this really sucks the battery, so you'll get much more if you're only typing emails and stuff, but very useful when you've seen all the IFE!) and replacement batteries are cheap anyway.