I just read via Wikipedia's entry on The Hangover that a sequel of The Hangover is in the works. My gut tells me that this will fail to recoup the successes of the original unless they are able to capture formal brilliance of the first. I thought The Hangover was a good, refreshing film, but mainly because of the way the plot was structured, rather than the quality of the humor (though, I have to admit, like many other critics of this film I thought that the composition of the cast was excellent - this may be another important point to the first film's success).
Back to the structure of the plot. The plot device was genius as a sort of emodiment of the experience of a hangover - stripping the characters of a portion of their memory, but making it imperative that they recover their memory in order to save their best friend (with the time-constraint that he is soon to be married). As a result, the film follows the usual result of a night of heavy drinking amongst friends: reconstructing the events bit-by-bit from what each person remembers or can discover from their surroundings (not that I'm too familiar with this process...). The only difference is that an artificial plot point was inserted to prod the characters on in this process - they must save their friend - which initiates another set of situations that they must navigate, such as taking Mike Tyson's tiger back to his house. This structure creates a sort of suture with the characters in the film, lending the viewer the excitement of trying to fill this memory-gap with the events of the night before.
What I think is perhaps most interesting about the film, as well as the point about the film that I may be most wrong about, is the purpose of the photos at the end of the film. I'd have to discuss this more with folks who have recently seen the film, because I saw this in the theater, so I could not go back and view the photos repeatedly (nor the rest of the film), but they seem to discredit what the characters have discovered throughout the film. If this is true, it would be a sort of last-second implementation of the Time-Image in the film. And, I think, a very clever one.
When I first saw the film, I understood these photos as rejecting what the characters had learned the night before, because you see photos such as wedding party winning a great deal of money with 'the asian gangster' Leslie Chow, but it seems as if Alan is the mastermind behind these wins. In this situation, they seem to be friends, working together, unlike the situations that arise during the memory-recovery portion of the film. Additionally, we see photos of Ed meeting Jade, which seem to suggest more than just 'I got married to a stripper' (and I would argue that these affect his future reality as he goes back to Vegas to date her). As a result, these photos make you resituate the main events of the film according to an alternate understanding of what has happened. What you think has been a recovery of reality is actually a fabrication in-of-itself, which illustrates the power of the Time-Image to recreate how we understand an event or narrative. And, even if I am wrong in the arguments I make about these events, I would still argue that the photos make the viewer resituation 'what has happened,' regardless of what meaning they take after this process has occurred.
What I think is most clever about the use of this formal playing with time, is the 'bemusedness' that results. Sure, some of the photos are amusing themelves, but what is more interesting is how they are reconciled with what had already come previously for the viewer.