It's been posted before, but it's cheaper and still holds its own against newer netbooks with their smaller screens and Intel shared graphics.
Operating system: Genuine Windows® XP Home Service Pack 3 (32-bit)
Intel Atom Processor N270
1.60 GHz, Level 2 cache 512 KB
1024 MB (1 x 1024 MB) RAM
160 GB SATA Hard Disk Drive 5400 rpm
11.6” Diagonal HD LED BrightView Widescreen Display, Resolution: 1366 x 768
NVIDIA ION LE
With patches from http://myhpmini.com/forum/viewtopic.php?f=62&t=2898
the ION LE can be unlocked to a full ION, which is nice. Add in one of the modified BIOS and the processor can go up to around 2.0GHz. Not bad.
Don't forget 5% Quidco at the moment.