For those of you who have a PI novel on your hard drive you might consider The Best Private Eye Novel Competition sponsored by Minotaur Books and the PWA. The deadline is July 1 and there is no fee to enter. The prize is publication and a $10,000 advance against royalties. You can find all the details here, just scroll down the page as the first two competitions are closed.
UPDATE: April 3, 2016 - According to the PWA website there will be no competition until they acquire a new sponser.