I've been collecting resources for about a week building a challenge course, which combines reflexes, puzzle solving and Minecraft physics all into one glass building. It isn't done, but the first 3 levels are more or less complete. If you'd like to try it out, visit 3324 on SMP2. Right now I'm working on getting the glass walls finished, and replacing the dirt and other random materials I used with stone and cobble. There will be at least two more levels, for levels 1-5 with multiple challenges per level.
