Here you go:

• Nice Patterns - Over a hundred images, they can add a real nice touch to your website, example here: http://www.whatdoiknow.org/]
• Damask - sweet sweet damask
• K10K's Style

I like it, Allen, I like it...

Could do with adding these links to the Database, they'd be really helpful to new visitors...

True... We should have a post there for graphic image collections for use, tutorials, etc.

A great portion of the backgrounds on that site are nice.

If you can design your own backgrounds, K10k has launched a Pixel Pattern Exhibition and invites you to submit your designs.

Ohh...NICE

"Damask, once restricted to formal rooms, has today come into much more general use than ever before in its long history. In this adaptation to our 20th century life, two extremes of patterns have evolved. One is characterized by new colour effects, the other simulates a fabric dulled and worn by age. And under good decorators or discriminating householders, damask-covered furni- ture and window and other draperies are successfully associated with fine furnishings of many periods, including our own."

Original post is updated with a link to some fine damask backrounds.

Updated the original post with a link to K10K's swell library of nice backgrounds

Here's a site I didn't know about until now:

http://www.textureking.com/

Large variety of background textures - most have quite large file sizes, so if you attempt to use them on your website, please be friendly to your users and shrink the file size