Here’s some themes I have done for Wordpress. I haven’t tested them in 2.3, but I have tested them in other versions as well as WPMU. License is GNU with CC on the graphics works. That means leave my credit please.

R3tro:

Flexible-width content area and fixed sidebars. Widgetized with font size and style options, as well as the ability to change the color scheme. Default is pink and you can choose from green and blue. Screen shows all three options at once. Download

Winter:

Fixed-width has options to change, such as flipping the sidebar from left to right, changing the font style and size, and is widgetized. Zip also includes the GIMP file to make or edit your own banner, and a second Icy banner. Download
(to do: add custom header option.)

More coming soon!