What grant project listed there will produce the most utilons?
My first guess would be the General Fund, as SIAI employees would then be free to choose the topics they feel are most effective at achieving their goals, and they benefit from the most motivation and knowledge of the topics at hand.
However, they have insider views, which may skew their interpretation of the value some projects will produce. It also appears they want to signal that they will accept guidance from outside in the form of donations to specific projects, or are attempting to solicit donations from people who otherwise would not have donated had they not known where their money was going.
The latter doesn't appear to be working very well considering the low dollar figure of donations outside the general fund, and may in fact prove discouraging to those few who attempted to fund their pet project. If this is true, then I would suggest only allowing donations to specific projects as a special case.
I am the kind of donor who is much more motivated to give by seeing what specific projects are on offer. The reason boils down to the fact that I have slightly different values (namely, hedonistic utilitarianism focused on suffering) than the average of the SIAI decision-makers and so want to impose those values as much as I can.
In case you missed the notice at the SIAI Blog, the Singularity Institute's next Challenge Grant is now running - $100,000 of matching funds for all donations until February 28th, 2010. If you want your donation to be tax-deductible in the U.S. for 2009, donations postmarked by December 31st will be counted for this tax year.