Hollywood stars got out their best wannabe-Woodstock outfits for the music festival in California over the weekend.
Paris Hilton transformed from "it girl" to "flower child", Katy Perry borrowed her grandma's underwear and Kate Bosworth tackled the non-existent mud in a pair of daggy old wellies (that she probably paid $500 for).
Check out the pics!
Caution: Epic hipster fashion ahead ...