Two things:
1) If I haven't mentioned it before, you can find a noticeboard behind the Rupture Farms portal. If you want more frequent updates (but who does? :P), look there.
2)
Suggestions for set pieces for the RF map are welcome. 
Players will be expected to make their way through the factory to "rescue" re-skinned villagers while encountering the occasional hazard along the many catwalks and rooms - "Save" enough villagers and the exit door will open, allowing players to escape. While I am coming up with some new ideas for hazards occasionally, perhaps other people's suggestions would speed me up a little.
Players will see a credits board by the spawn point in the finished map before they board a minecart to RF, so people who create stuff that I end up using will be posted there.
Any idea is welcome
provided it can be used in original, un-modded Minecraft, but bear in mind that some ideas are good on paper but end up not working 'cause of Minecrafts crappy limitations (For example I was planning to use falling sand to knock players down who are jumping over gaps, but it just passes through them harmlessly). You're always free to try out stuff yourself in creative mode.

Also bear in mind that the only mod of Minecraft I'm planing for this will be a texture pack, which won't change very much.
There is a way to start redstone timers by forcing the player through a doorway with a pressure pad at the start of a section of a level, so that's not an issue.