Hi,
apparently this hasn't been discussed here yet. About a month ago, Donncha O'Cearbhaill build https://oniontip.com/ during the Dublin Bitcoin Hackathon. It is a webapp which automatically extracts all Bitcoin addresses set in the ContactInfo variable of the torrc and distributes Bitcoin donations based on the consensus weight.
There are already 100+ relays listed which represent around 5% of the total consensus weight. In just a few weeks they distributed around 125 US$.
There are many other theoretical ways to provide compensation to tor relay operators (see https://blog.torproject.org/blog/tor-incentives-research-roundup-goldstar-pa...) but I really like this very simple and practical approach.
Thoughts?