Katy Perry Lindsay EllingsonNell Diamond

Some well-heeled ladies showed up ready to impress at Tuesday night's 9th Annual UNICEF Snowflake Ball, which took place at Cipriani Wall Street. Just one amazing look wasn't enough for UNICEF Goodwill Ambassador, Katy Perry, who made a head-turning costume change for her performance. Click through to see both of her gowns, as well as all of the other guests who won us over last night.

[All photos courtesy of Getty]