It seems Facebook's long-rumored music offering is a lock for tomorrow's f8 developer conference — or at least, that's the impression we're getting from an over-anxious employee who slipped a few details a little early. The company's creative director Ji Lee mentioned a "listen with your friend" feature that was "blowing [his] mind" on Twitter earlier this evening. The tweet, which has since been deleted, also mentions integration with Facebook's Ticker — the new live feed that remains docked to the top right of your News Feed. The service is also rumored to have a "scrobbling" feature that will send real-time track information to Facebook, and is also said to work with multiple streaming services. We'll be there live tomorrow to bring you all the news live tomorrow. Stay tuned.