Just bought an IBM T43. £1k for Centrino 1.8, 512Mb, CDRW, 15.1", Bluetooth (why?), fingerprint reader (more useful than you'd think!). I'd never touch anything other than IBM, but then I'm tough on lappys. My last Compaq was a steaming pile of ****e. I only bothered with a decent spec because I tend to do a bit of 3D and some image manipulation, otherwise anything made in the last four years would be fine.
Cheers,
Ali