Fear and Loathing in Las Vegas

I don't really know where to begin to review this movie. In fact, I can't even figure out what genre to put it in. IMDB says that it is a comedy/drama/biography/fantasy...I don't really know how a movie can be all of those things. This is a story of two men on a drug induced frenzy in Las Vegas and was adapted from a Hunter S. Thompson novel which was partially autobiographical and based on actual events in his life. Johnny Depp and Benicio Del Toro were a natural duo and really captured the essence of drug addicts. Their acting was incredible, but I was unable to understand Depp during most of the movie. Luckily the narration cleared up most of the confusion. This movie was completely off the wall...but I will admit, I laughed several times, especially during the beginning scene with dialogue that goes something like this:

Raoul Duke: [narrating] We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember saying something like:
Raoul Duke: I feel a bit lightheaded. Maybe you should drive.
Raoul Duke: [narrating] Suddenly, there was a terrible roar all around us, and the sky was full of what looked like huge bats, all swooping and screeching and diving around the car, and a voice was screaming:
Raoul Duke: Holy Jesus. What are these goddamn animals? [swatting the air]
Raoul Duke: Huh! Huh! Huh! F-ing pigs.
Dr. Gonzo: Did you say something?
Raoul Duke: Hm? Never mind. It's your turn to drive.
Raoul Duke: [narrating] No point in mentioning these bats, I thought. Poor bastard will see them soon enough.

I laugh because this doesn't make any sense...in fact, the entire movie didn't really make any sense. Dan hated this film...I thought it was funny, but it was all over the place and did not appear to have any specific plot, which keeps me from loving it. I did, however, love the cameos from dozens of actors, including Tobey McGuire, Christina Ricci, Cameron Diaz, Christopher Meloni, Flea, and Lyle Lovett. But I don't feel this movie rates any higher than 1 pig.