I like game design contests, they help me focus my thoughts, they give a deadline, and they provide an immediate audience of other designers who'll look at my stuff.
With this in mind, I'm happy that I've found out about the...
Shortest Month, Longest Game – Design Challenge
I'm not sure if I'll be participating at this time, but it's good to keep in mind.
None of the projects I've currently got in mind are currently a match for the ingredients offered in the contest, but if I stew on some concepts for a while, I might come up with something.
Go over, take a look.