The first Stick Figure Porn Contest was launched on AdultFriendFinder in 2009, and attracted hundreds of stick figure drawings.
The current contest is open now, and can be seen here.
Stick figures of all mediums are acceptable. The contest is free to enter. Participants will need to sign up for a free AdultFriendFinder account in order to post their drawings. The deadline to enter is March 14.
First place is a free one-year gold membership on AdultFriendFinder.