We decided to ask ourselves one question: How to we validate an idea before wasting months on an idea that only we seem to think is cool?
So we are creating WillThisFly? to ask that very question... it's a site that allows you to try out your ideas and projects, get feedback and refine them before committing resources to it.
Shameless plug: http://willthisfly.net (Just launched last night)
Only thing on there at the moment is WTF? itself.
All I can say is, it has happened to probably everyone at one stage in their startup career... don't give up, refine your ideas, create MVP's and keep trying...