I just saw this movie at a sneak preview and all I can say is..."What did I just watch????" And I mean that in a good and bad way.
The plot is really simple. Stiller and Black play friends/neighbors. Stiller is the focused, hardworker while Black is a dreamer. Black invents this idea to create a spray that erases poo. The idea becomes very popular, and Black becomes very rich. The extravagant lifestyle that Black gains and the fact that he still tries to be best friends with Stiller causes Stiller to become crazy with envy.
As I said, the plot is simple. Everything else is plain odd. The direction is odd, with a weird rotating opening shot to out-of-nowhere sped up sequences. The dialouge and the acting is very odd; odd in a rambling sort of way. And the sound track is the oddest thing in the movie, from the weird "Envy" song that keeps on reappearing to the scene where you think you're going to hear a classic 80's song but suddenly it's in Japanese.
So, the true question is this...is odd funny? That depends purely on the individual. I was cracking up at the shear unwavering weirdness of the movie. After the screening I heard people call it horribly unfunny and glad that it was free. Strangely, I understood their point. There are no jokes whatsoever, so if you aren't hooked by the uniqueness of it all, you will hate this movie. Absolutely hate it.
This movie is destined to lose a lot of money at the box office and become a DVD cult classic. If you can laugh at a movie with no real jokes, like Cable Guy or Punch Drunk Love, then I suggest you see it. If you don't, run away from this movie. It'll only make you mad.