I've seen a few posts on here about all the different alternative YC groups found by people who were denied an interview. First of all, don't stop. It's not the end of the world if pg denied you an interview, so continue on making your idea.

His post said specifically said that your idea isn't "bad" just not "exceptional". You now have six months to build a better application. You can work on making the demo better, and spend some extra time to figure out some of the more important questions. (ie. How exactly are you going to monetize?)

I've seen a lot of discussion about alternative YCs. They all sound like a good idea, but what's so hard about bootstrapping? Just spend a few extra hours after work on your project. Get things going nice and smoothly. Who knows, you might not even need YC at all!

I applied for the previous Winter `08, and I didn't even get an interview. My partner and I decided to go ahead without YC. Things have been slow, but we haven't given up yet! (Also, take a shameless blog mention from me. ;) http://fangamer.com )