I had a similar problem. Had a 5yr old laptop and a more or less new one, but the new one i used for downloading and rebooted it regualry from viruses, and also it was a little chunky to take to uni each day (15.1" screen)
So i have just got of ebay a 14.1" IBT T43, cost £300 with delivery, and has all the specs i wanted.
I looked at new lenovos for £400 but found i can get a better secondhand ibm for around 300 that has warrenty and much better spec.
It has 16 month warranty, a 92% battery, and spec wise, 2ghz centrino, 2MB Cache, 80GB HDD, 1GB RAM, DVD-RW, 64MB Dedid graphics
and has the usual ibm trimmings of wifi, bluetooth and finerprint reader.
Its a really light machine, great battery of 4hrs in current state and the build quality compared with Dell and Acer is far far superior, and the build quliaty compared with Sony and HP is still better.
Nice solid machine, just its second hand and is just normal centrino.
OH - It has windows XP too which might be a result for some people...