You could just click this link where I have all those options already selected. Go down the list until you find a good Thinkpad T400 or T500.
laptop | eBay
Here's a good T400 from that list.
Lenovo T400 14 1" Laptop Core2Duo 2 40 GHz 4GB RAM 150GB HDD DVD | eBay
Here's another T400 from that list.
Lenovo ThinkPad T400 Laptop Notebook Core 2 Duo 2 53GHz 4GB 250GB Win7 Bluetooth | eBay
Here's a T500 that I might get before you get to it... I kinda need one myself, to replace a slow laptop in my current lineup.
Lenovo ThinkPad T500 Core 2 Duo T9400 2 53GHz 80GB 4GB DVD RW 15 4" w Win 7 | eBay
laptop | eBay
Here's a good T400 from that list.
Lenovo T400 14 1" Laptop Core2Duo 2 40 GHz 4GB RAM 150GB HDD DVD | eBay
Here's another T400 from that list.
Lenovo ThinkPad T400 Laptop Notebook Core 2 Duo 2 53GHz 4GB 250GB Win7 Bluetooth | eBay
Here's a T500 that I might get before you get to it... I kinda need one myself, to replace a slow laptop in my current lineup.
Lenovo ThinkPad T500 Core 2 Duo T9400 2 53GHz 80GB 4GB DVD RW 15 4" w Win 7 | eBay