Funnyformoney.com has a weekly contest where you can win cash! To enter, you submit a punchline via video in response to their topics. If your punchline gets the most votes, you can win $500! You also can win $500 just for voting on your favorite punchline.
Here is the link to sign up and to view the current entries. New topics are submitted every Monday. This week's contest is coming to a close, the new contest should start tomorrow (Monday, September 19th, 2011). I'm gonna submit some entries myself this week. Join in on the fun... it's going to be a blast!
Here is the link to sign up for the contest and where you can view and vote on current entries: