This month we can all finally own a copy of The Hangover on DVD, but the fun is rolling on through the new year! Jan. 1 has been declared National Hangover Day (something we can all relate to), and the film's cast is getting in on the fun with some cute PSAs. First we've got an exclusive sneak peek at the DVD extras with this fun behind-the-scenes look at what it was like on the set. Watch as Ed Helms, Heather Graham, and Zach Galifianakis show us what it was like filming the movie in Vegas's The Riviera.
To see Rachel Harris's PSA, just