BOINCstats accepts GRIDCOIN as on their donation page:
Crypto address: RzXRNQU8rBwS2VSAzP4vzk5ug2wnZKUP5H

I have sent some coins previously and it worked, at least I assume so. Yes, I am one of those, who send small amounts of GRIDCOINs to various initiatives around BOINC and GRIDCOINs as donation from time to time.