See where the stars ended up last night.
•Pauly D helped Cosmo celebrate the launch of its new iPad app [Getty]
• Martha Stewart, Wynton Marsalis, designer Zac Posen and many others raised funds for the tsunami-struck country of Japan at a benefit [Guest of a Guest]
• The dashing Penn Badgley watched the premiere of "Margin Call" [Getty]
•Michelle Trachtenberg, "30 Rock's" Katrina Bowden, and Selita Ebanks helped Rebecca Taylor open her new Meatpacking District store [Guest of a Guest]
