nicepc.co.uk do some really good deals on fujitsu laptops. I got myself a fujitsu amilo d 8830 with pentium 4 3.06 (with hyper threading technology)
512 ddr ram, ati radeon 64mb graphics card, 5 usb 2.0 ports! a fire wire port, cd/rw, dvd player 4 £1000 I think there selling them for £950 now though.

Im running traktor on my laptop (through final scratch) and it works quickly & smoothly.