Fundrace.org This is a nice site which shows how much people are donating to the different US presidential candidates. You can search by address and neighborhood. Who is your neighbor supporting? It also provide maps of the country and of big cities showing the breakdown in contributions.
One interesting fact is that George Bush gets most of the small donations ($50). Meanwhile, John Kerry gets the highest percentage of big donors. This surprised me as supposedly the Republicans are the party of the rich. I guess a lot of average joe's are putting their money on Bush and a lot of rich folks are rooting for Kerry.