I'd never heard of the Waffle House Index, but I think it's pretty cool.
I'm a fan of "alternative" economic indicators such as this. I'm actually developing one of my own, the TBiP.
I got my dogs a couple years before the housing market blew up. Every night during our walk we would go by an apartment complex with a tennis court and a pond. People would be out late playing tennis, and there were regularly several tennis balls in the pond. After the housing market crashed I noticed a steep reduction in the number of Tennis Balls in Pond. Maybe because people had less time to play tennis, or chose to live in (cheaper) apartments without a tennis court, or fetched their balls out of the pond instead of just buying new ones. But there seemed to be a correlation.
I'm still waiting to hear back from the CBOE, CMT, and NYSE, but if in the meantime you'd like to trade on TBiP futures, just send me the money and I'll let you know how you did.