Just to put this out there from the get-go, I wouldn't recommend this movie to kids any younger than me (16). It is packed full of crass sexual jokes and language.
Aside from that, I thought it was really funny. The impossible scenarios, the racial jokes between the israelis and the palestinians, and of course the whole idea that a counter-terrorist agent would want to "make the people's hair silky-smooth" is hilarious.
Adam Sandler does a great job with taking on a Middle-Eastern accent; I wonder how he could keep a straight face. The special effects were absurd but at the same time realistic, so it's not like it was a poorly-made comedy.
However, to me this movie seemed like they switched directors halfway through. The first half of the movie is really funny, and maybe its just that once you get used to the behaviors it's not as funny, but the second half was a bit less than hilarious. It was filled more with crass, awkward jokes than ones that would make you really laugh hard.
A comedy is the hardest movie for me to rate highly, but this one was funny enough to get atleast a 3.