An article in today's New York Times indicated that 10021 (Marymount Manhattan College) is the top zipcode in the nation when it comes to campaign contributions. Interestingly it is #1 for both democratic and republican in terms of money collected by the 2008 presidential candidates.
You can read/research the FEC's campaign finance reports directly at their website.
Also opensecrets.org provides a wealth of information about past and upcoming (2008) elections.
You can play with a Google mashup of this data here.