Once again I find I have to be a total asshole and post the following article. It's hurtful, rude and at times very insensitive, but recent circumstances demand it. Still, pretty much every writer I know has felt this way at one time, and,if you are an aspiring screenwriter who someday sells their work, I guarantee at some time you will feel this way, too.
So, without further apologies:
http://blogs.villagevoice.com/runninsca