Hey, MAPlight.org, funded by Sunlight Foundation, builds online tools to show where money goes in Congress and what they get. Here's a good case:
Yesterday the US Senate voted against the energy bill (S.3044 – Consumer-First Energy Act of 2008 ). According to Reuters, "the energy package would revoke $17 billion in tax breaks extended to big oil companies like Exxon Mobil Corp and slap a 25 percent windfall profits tax on firms that don't invest in new energy sources."
MAPLight.org's research team revealed that oil producers gave an average of $134,821 to each of the 43 senators that voted no and an average of $37,373 to each of the 51 senators that voted yes.
Details are here.
This is why we need the political reforms pushed by Senator Obama, and opposed by Senator McCain.