There are quite a few, read herds, of people who enjoy the cartoon-ish, hat wearing, customization filled game Team Fortress 2. Quite a few of these people happen to be talented in things other than stabbing people in the back while wearing a paper mask or lighting said spy on fire while shouting incoherent phrases through a gas mask. If you do love or enjoy TF2 or simply want to dabble in making maps for video games here is your chance. The folks over at TF2Maps.net are hosting a Payload Map contest. Participants are encourage to design a single stage payload (a game type) map before April 30. If you want to do well though your map will need to feature a “dynamic element.”
A “dynamic element” is purposely vague it seems. While it can be something that “involves moving, turning, lifting, teleporting, cloning or turbo-boosting the payload cart,” it could just as easily be something that you think of which naturally adds excitement and is well designed. Unfortunately my idea of having the cart take off into space while leaving a trail of hats behind it was shot down but I have faith in the creativity of the community and look forward to outlandish and cool creations you make.
The TF2Maps community just so happens to be the largest custom map community for TF2 and Valve appears to be fairly active in watching popular maps so your submission might just make it into an official map release if you do really well. More information and the official rules of the contest can be found here.