It's time for businesses to get out of politics. Candidates, political parties, and political action committees should only be able to accept contributions from individuals. This means no corporate sponsorship of candidates, no political ads sponsored by businesses. I would even forbid groups from donating. No unions, church groups, clubs, etc. would be allowed to donate. The individual members should be allowed to freely donate but groups will be forbidden.
There are millions of dollars flowing into DC and who knows what kind of legislation it's buying. I think the Jack Abramoff scandal is the tip of the iceburg. The corruption needs to stop, but it won't until the money dries up. Businesses do not have the best interests of the country in mind. They need to get out of politics.
Update (Nov 2, 2006)
Another way which has been pretty effective in Arizona would be using a clean elections type financing model. The way it works in Arizona is that a candidate running under clean elections must get a certain number of $5 donations from individuals (the number depends on the office they're running for). Once these donations are validated, the candidate gets a certain amount of money (again, dependant on the office) for the primary and a certain amount for the election. If their opponent spends more, the candidate also gets more. This keeps the amount of money spent equal and makes the campaign more about issues than money.
People complain that it favors the incumbent due to name recognition and by not allowing a challenger to outspend their opponent. However, the incumbent is favored anyway and what if a challenger is great at politics but lousy at raising money? Is it fair that the they biggest and/or most effective schmoozer almost always wins? I think clean elections has worked well in Arizona and I would love to see it go national.