I get pretty good battery life out of my compaq presario 2143EA (i know its a compaq.... Shudder

)
2500+ XP-M
512MB DDR 266Mhz
40GB hdd
integrated 11MBps wireless lan (Mini-PCI internal)
CDRW/DVDROM combo
Ati IGP 320 (Radeon 7XXX varient)
15" TFT
And the best bit is if you buy off ebay you can have this not amazing but pretty good value laptop for about £500 excVAT