Check http://dice.com/ enter your favorite (desired) language and skills and take a look at the trends, use http://www.indeed.com/jobtrends to analyze this trends in depth (well, in ``depth'').
Go to berlios.de, sf.net and check "Help wanted" section. Find an correlation between trends at job market, your goals and project which are currently looking for developers, choose right one.
Slashdot Mirror
Go to berlios.de, sf.net and check "Help wanted" section. Find an correlation between trends at job market, your goals and project which are currently looking for developers, choose right one.
Enjoy.