Compaq NC4400

Pros:
Sturdy...
Nipple/joystick thingy for the thinkpad fans.
Keyboard layout.

Cons:
This HP although sturdy in most parts, the screen has a little flex. And there have been reports of poor build quality on the keyboard.
Although it is small, I think it could have avoided ports at the rear.

Sont Vaio TZ

Pros:
Small and light, whilst including a DVDRW drive.
Sharp screen.
Good keyboard.

Cons:
Comes with Vista only.
Lots of bloatware.

Sony Vaio BX61VN

Pros:
Keyboard, CTRL on the bottom left (and not Fn key!)
Nobble "Thinkpad" joystick (if that's what you are looking for)
No bloatware!

Cons:
Only 3 USbs, small amount for it's size.
Looks solid, but feels flexi and cheap
Ports at the back