out of curiousity, how much bandwidth do we require to host an Speedtest.net Server?
Depends who is "we" and depends on your audience. If "we" is Beam, then they probably have enough bandwidth: a public one should be connected with at least 1gbit/s - you couldn't really host it at home or anything, and a lot of webhost companies might get peeved if you took credit for their bandwidth (there's speedtest mini for both those applications).