UserVoice for congressional districts as an alternative to lobbyists.
The idea is to use technology to disrupt traditional lobbying to the point that it is more difficult for the bad lobbyists to have a negative impact.
With the science of reputation and filtering systems getting better by the day, one solution might be a service that makes everyone a potential lobbyist. There are about 118,000 citizens per pair of ears in Washington according to Clay Johnson, author of the blog InfoVegan. The website I am suggesting would allow all 118,000 people an equal chance to voice their opinion. Those 118,000 opinions are then voted one by those same 118,000 people. The most upvoted items "float" to the top and get past the filter to the Congressman or Congresswoman's ears.
If you also make it so that people can't link and vote for opinions directly, you remove the one major avenue used to game the system: one person with too much time or influence spreads the link to their idea to those likely to upvote it.
Instead the system can be designed like a double-blind experiment. Ideas are stripped of names of people and organizations. The system randomly assigns ideas already submitted to be upvoted or downvoted to all participants. A participants ideas does not get submitted for voting by others until they have "bought" that right by voting on the ideas of others. Participants get a limited number of upvotes and downvotes to use, thus preventing them from giving out too many of one or the other and being forced to make a judgment call.
Those are a few ideas, but there is no reason the mechanics of voting and reputation systems can't be used for this end.
As I said above, this is a bit like UserVoice for government in that it allows users (citizens) to "lobby" the product managers (congressmen and congresswomen) for product feature requests and improvements.