Why pay celebrities to appear in commercials when you can pay them to party? Corporate sponsorships have popped up at the soirees of famous faces ranging from Shaquille O'Neal to Tori Spelling.
John Mayer and his father celebrated their birthdays together last year, courtesy of Blackberry, according to InStyle. The younger Mayer turned 30, while his father, Richard, hit the big 8-0 at New York City's Rainbow Room.
(Evan Agostini/AP Photo)