I love the nice clean design.
Some kinda nit picky things:
- The sponsors thing on the side is nice, but it would be nice if you could make the "sponsors page" a hyperlink to the correct page.
- Maybe the tabs could change on hover to a slightly different color? And maybe you could have it be that color if you happen to be on that page. The second is a little harder, depending on how you generate it in the PHP.
The FBW (Future Browsers of the World) really appreciate the valid HTML. You almost also have valid CSS, but
"strike" doesn't appear to be valid... don't know what you should use.
Overall, very nice!