The treasure hunt ended Saturday, September 27, 2014. Thanks to everyone who took part.
Not counting the extra group theory problems, 8 people took part in the treasure hunt. Here are the list ranked by number of problems solved.
Clicking on the address gives a PGP signed certificate (by my public key) indicating that the owner of the address participated.
Three other participants solved 4 of the "extra" 7 group theory problems:
13eTCGuu6dH7fkSfQQDaq9AYAhhpQYrJ7v solved 2 of the group theory problems.
12VTC6QB8Gd3tQy5oKr7FnvY7uK8jCZphq solved 1 of the group theory problems. I gave some (public) help in a reddit thread.
16HvHkZvBxZTmENBFk1y7KDconKm3J2yQR "solved" 1 of the group theory problems by cut-and-paste. I had publicly posted the solution on the same reddit thread in an attempt to spark some interest in the treasure hunt.