Fundrace2008 is an interesting site that maps the donations to political parties. Not only can you find out who your neighbors are supporting, but also which occupations give money to which party. For example, inserting 'insurance' in the 'occupation' section yields these data:
Republicans - $330,000
The occupation 'teaching' yields this data:
The occupation 'self-employed' yields:
The occupation 'banking' yields:
Interesting stuff to ponder and play with if you have the time.