It is indeed not an easy thing to do, especially at the current size of the community (a few thousand).
I do have imperfect location data for many members, so if anyone wants to initiate a meetup somewhere I can ping those who happen to be nearby, plus include info about the meetup in the newsletter, etc.
For planning different meetups we can of course use the Locations forum.
Another thought I had was to piggyback on other relevant meetups already being organized. Perhaps we could list relevant Meetup.com and Facebook groups for different locations, and then we could go together to those?
Got any other ideas @lewis?