I propose we have this thread as a prefab dump with included pictures if possible, that would be pretty sweet especially since many beginners don't have them or know where to get good ones. I know I'm a bit late here but I thought it would be good to share this one with the rest of the community. That one thing I have to contribute is a good quality (In My Opinion) test chamber door prefab, that does not have any holes and perfectly fits in to walls, for use with the Swarm SDK and you can download it here:

http://www.mediafire.com/?0o9r7tpnk9rjmvv

http://i1206.photobucket.com/albums/bb451/Chopsticksz/HammerPrefab.jpg
http://i1206.photobucket.com/albums/bb451/Chopsticksz/2011-04-29_00001.jpg

Upload any new files to the Download Database. Don't link to external files. Thanks.