Allow the people to supplement govt programs of their choice via tax refund worksheet.

The idea is simple. I will use myself as an example:
I received a tax refund for $1xxx in 2010. In 2010, NASA's fiscal budget was a little lower than I would have liked it to be.
I propose a worksheet, which could be electronic, that would allow taxpayers to supplement the taxes they have already paid. Instead of being fought over by Congress, this money comes out of the taxpayers REFUND, and will give x amount to the taxpayers govt program(s) of choice.
Why do this?
If taxpayers are putting significantly more money into certain programs than Congress is, a disparity will appear. This will allow Congress to modify their yearly fiscal planning to better match what the people want.
In action.
When I file my 2011 taxes, I want to be able to supplement NASA directly with x/y of my refund