From the website, under Frequently Asked Questions, we have this:

Where did the Ø7Ø Club originate?
The original idea was proposed by Jay, N3DQU, likely inspired by then recent events in the Penn-Ohio DX Society and in the ham radio hobby. The idea was to form a club that offers hams incentives to use PSK31, one of Amateur radio’s newest digital modes. The Ø7Ø Club was launched in June 2000 by PODXS, with Jay, KA3X (the old dude, now SK) achieving number 001 in record time. The Ø7Ø Club name arose from the PSK31 frequencies on 40, 20, and 15 meters ending in 070. PODXS and the Ø7Ø Club, continuing to grow with, and for, amateur radio.

As for Rollo, I hope Steve chimes in on that one.  

Jim K5SP