thelinuxlink.net

Starting at $600, models include:

Dimension E520 N
Inspiron E1505 N
XPS 410 N

Here's hoping Lenovo, HP, and Toshiba follow suit.

http://www.dell.com/open
http://www.desktoplinux.com/news/NS7075656310.html

Dell has mentioned in the past that these Ubuntu boxes would be cheaper than their Windows counterparts, I just took a look to see whether they kept their promise, and guess what, they did!

Look at this:
http://www.irisnebula.net/DellVista.ps
http://www.irisnebula.net/DellUbuntu.ps

The Ubuntu machine is exactly 50 bucks cheaper than the machine with Vista Home Premium. This is exactly the amount I suspected the Windows tax to be.
The two machines that's shown in those two PostScript files (Courtesy of yours truly), are configured to be as similar as possible, I'd expect the to physically identical.

In england Lenovo are bought from third party suppliers never direct, there are places that sell it with linux

Such a company is http://www.linuxemporium.co.uk/products/laptops/

Sadly there expensive, you could properly get the same laptop with windows cheapers