Kolja Keller, a PhD student at the University of Rochester, calls my attention to this site which solicits students to rate their programs by e-mail with an offer of a $5 Starbucks e-card.  The site itself does not reveal how many responses each program received, or how many students from different programs participated in this exercise. 

(About a decade ago, we tried to collect student feedback on programs for the PGR, and it was a disaster for two reasons:  first, some programs lobbied their students to send glowing reports, while for other programs we heard only from one or two people, invariably people who were unhappy, and we had no way of determining whether or not they were representative.)