Pete:
Be careful - you're actually advocating a free market idea. Paying someone an agreed-upon rate for transfer of a good or service.
If BP is going to be forced into cleaning up the oil spill - which btw, the Federal Government is supposed to do - then what you suggest wouldn't be such a bad idea. Lord knows it would help "motivate" some of the Obama-economy-unemployed to take up a side job for the next few months.
But I have a feeling that this is going to happen anyways. People will be employed to help clean up the spill. What you're proposing is simply encouraging faster cleanup by paying the clean up workers based on how much they collect.
If you didn't present your idea with the intrinsic hatred and disdain for all things-private enterprise Pete, you might find more support.