There's this documentary called "The Great Global Warming Swindle" that I've seen bits of that gives a bunch of pretty convincing arguments against the whole thing. I've yet to see the whole thing, though.
I dunno, I think it would be stupid to ignore the whole thing completely. Obviously stuff humans are doing aren't great for the environment and will probably come back to bite us in the ass someday, but I don't believe in this "Earth will be totally flooded in 25 years" stuff.
I do think we need to quit wasting resources and come up with a new way of getting power right away - not because it's causing the earth to warm, necessarily, but rather because once we do find a new power source, we're going to need all the fossil fuels we've got to make the transition.
However, I was discussing this with my cousin one day and she made a pretty good point. She said something like, "Well, I'm still of the mindset where if you need to lie to people a little bit to get them scared enough to do something, then I think that's understandable. People are stupid and lazy and won't make any effort towards any real change unless they think the world is coming to an end."
And, you know. She's right. So while I don't think it's as big of a deal (yet) as say, Al Gore is making it out to be, I can understand why such a big deal is being made.