Gwen Stefani Joins Gavin Rossdale on Stage in L.A.

"They haven't done it in at least a decade," says a source. "They thought it would be fun"

Source: http://feeds.people.com/~r/people/headlines/~3/2F6cQxvmU60/0,,20655114,00.html

Aubrey ODay Audrina Patridge Autumn Reeser Avril Lavigne Bali Rodriguez Bar Refaeli Beyoncé Bianca Kajlich