John Varvatos V729 - Ken Jeong - The Hangover
These John Varvatos sunglasses can be clearly seen on the movie poster with Ken Jeong.
There are several color combinations for these glasses, but the correct version (as seen in the movie) is the John Varvatos V729 with Silver frame.
Thanks to Wayne for the ID
Reference: John Varvatos V729 - Color: silver