Can we have at least partial control over how our donation is spent?

It would be nice to allocate x% of our donation to go to specific 
projects we value and have the remaining y% decided by Ruby Central. To 
keep things simple, x and y can be 50% each.

For example, it might be attractive for people to be able to say, 
"here's $250, I'd like a portion of it to fund bounties for ruby-dl2, 
wxruby-swig, or rubygems."