Single in the Summer!
Travis Barker and Shanna Moakler
Perhaps the most notable on-again, off-again Hollywood couple, Barker and Moakler split again in April. The couple -- who divorced in 2004 but reconciled last September after Barker's near-fatal plane crash -- called it quits "after a nasty fight broke out at his house last night and cops were called...[when] Shanna started freaking out and acting irrational," a source tells Us. They have two children together.