Ya’ know, you can just blow off the whole spec script thing, shoot a trailer, and sell it in a bidding war just like these guys did:

[youtube=http://www.youtube.com/watch?v=ehNFPShWTsg]
Of course, it helps if “these guys” are Seth Rogen and Jay Baruchel. And you’re working with a great high concept: two slackers stuck together in a post-apocalyptic world.