Yeah, Offset should become default really. :)
Other ideas I had while looking through the site:
The header of the [Plans, possible improvements]-page should say what the link says or vice versa. [GLtron - Project plan] And get rid of the schedule-dates on the page.
The "forum"-link should match the rest of the navigation, so: [Forum on ScourceForge].
Merge [Documentation] and [FAQ]. These are both place to seek for information.
The Links-section in [Documentation] unneeded. Place these under [Links]
The [Screenshots]-page needs an update. Better yet: Ask your users to send in their best shots. Put the best one on the new [News]-page. And place some more shots freely on the site, eg in the Downloads-section.
GLTron can produce such terrific views - use this!
The Navigation links should have their own CCS-class so they don't get underlined and marked as visited.
Think about getting rid of that background-pic... White or lightly greyish bg-color would make a big difference.
Finally: If you don't have much time for webwork (we'd rather see you coding anway ;) ask here on the forums if some fan with an appropiate background in webdesign will do it for free.