As is mentioned on the ServerGrove blog (here) the Symfony project is holding a contest to get help from the community and offer monthly prizes.
Pascal Borreli came up with a great idea to involve the symfony developer community and advance the development of the framework. The event is called one-day-one-ticket and it will give monthly prizes to the developer that fixes the most bugs in symfony. While it is still a good idea to contribute to the community anyway and get your merit badges, a little extra incentive always helps.
This post on the Symfony blog gets more into the details of the contest. To enter you have to sign up and close one ticket a day for the month. You'll then be entered to win one of that month's prizes including copies of books, a "surprise gift" or a contribution from ServerGrove.