1. Build a prop room (those areas with all the computers and stuff) along with the adjacent room (can be a hallway, spawn room capture point etc).
2. Fit a complete CP map within a small space 1024x1024x1024 (Yay trends!
)
3. Make an asymmetrical CTF map.
4. Round robin. Not really a contest, but what if everyone works on one map? IE: Person A starts it, passes it to B, who adds a section, passes to C etc... Everyone adds their own "touch" to the map. Could make an EXCELLENT learning opportunity (everyone groups their addition on a separate layer).