This was a completely unheard of movie from what I know, though it starred Tim Robbins, Patricia Arquette and Rhys Ifans (of "Notting Hill" and "The Replacements").
It's a strange story of "human nature" with some hilarious bits, some extremely strange situations, and bases ALL human nature on man's urge to fornicate. (which is probably somewhat true, why do we write books, invent things, have jobs, etc?).
The main characters are Lila, Nathan and Puff. All of whom have their little intricacies. Lila (played by Arquette) is a former circus freak/nature writer, who's got a hormone problem that makes her hairy all over her body. Nathan (Robbins) is a scientist with an Obsessive Compulsive Disorder with regards to manners. Puff (Ifans) is a man raised by apes, or more specifically, andother man who THOUGHT he was an ape.
The story then works to become a love triangle, or rectangle as it may be, as well as a quirky tale of Nature versus Nurture. It's a VERY Spike Jonez feeling production and has quirkiness similar to that of Being John Malkovich, but it's a little BETTER in that it's more receptive to a larger audience.
There are some genuninely funny scenes and lines, but if you'd like to hear them or know them, you'll have to check out the movie. If you liked Being John Malkovich, you should like this movie as it's got a comparable level of quirkiness to it yet remains comically sensible. I haven't shown this movie to someone I've met who hasn't liked it, though I've noticed some terrible reviews for it. If you're not sure, check it out. It looks like you'll either love it or hate it. At least it provokes some feeling either way.