I think it's a great idea, Jeri. A way to address the regional issues could be to post whatever session lists are available. Hartford (Conn., USA) Country Dance club posts a list of the most commonly used tunes at their dances (inviting musicians to join the band). A couple of slow jams in Rhode Island put out a list of tunes and the preferred key. Given some of the samples from the thread you blue-clickied and the global participation here, the Mudcat could be a focal point for putting together sort of a Fodor's Guide to Sessions (in Australia, US, Canada, Iceland, Ireland, England, etc). Handy for the musical traveler.