Where can I get stock footage?

[Angelshare1]

I'm making a politically charged film about the green movement and I need footage of a commodities market (or stock market) trading floor, Al Gore coming out on stage or doing a speech and a lawmaking body passing a law. (You know, the part where the speaker hits the gavel and everyone applauds at the new legislation.)

I was thinking of filming my own stock market, but wow, that'd be a lot of work for a few seconds of footage. (I actually did find a mothballed trading floor that would let me film.)

Thanks in advance!