There are also a few websites that sell computers with pre-loaded Linux and they offer more choices than many of the big-name vendors. Linux Pre-Loaded.com has links to various 3rd party vendors who sell Linux machines. As a convenient touch, they also list what country they ship to, in order to help narrow your searching.
Zareason.com sells both Asus netbooks with Linux and unbranded computers. They feature netbooks, laptops, and low-wattage, compact desktop systems. They even offer keyboards that replace that certain Redmond key with one sporting the image of a penguin or Ubuntu's logo. Nothing says you love Linux like that!
System76 is one of the better known Linux computer vendors. They sell laptops ranging from the 12.1" Darter Ultra to the 17" Bonobo Professional with a 500 GB drive. All laptops can be fitted with 4 GBs ram, Intel Core 2 Duo processors, and bluetooth. You can also show off your OS preference at the coffee shop with their bright-colored Ubuntu laptop case badge. Desktops start with the compact Koala Mini and go up to the Wild Dog Performance featuring 1 TB drive, 8 GB of ram, and an impressive 2 GB graphic card.
If you live in the UK, try Linux Emporium. They offer laptops and desktops with Ubuntu and also SUSE. They sell laptop brands from Asus and Lenovo, and desktops from Shuttle, which specializes in space-saving designs. Computers from Linux Emporium have one-year email support. They also sell CD sets of various Linux and BSD OS's. Unfortunately, they don't ship outside the UK.