Britney Spears headed back into a studio in West Hollywood yesterday. She's been hard at work on her album, Femme Fatale, all week but this time she had a special guest for the recording session. The Black Eyed Peas' Will.i.am joined her for a track that Britney says her fans are "gonna love." Will.i.am is coming off a Super Bowl half-time show that unfortunately couldn't involve live tweeting. We'll have to wait until March 29 for Britney's latest record since the release was recently pushed back, though Britney's full video for "Hold It Against Me" will be out at 9:56 p.m. on Feb. 17.