Another geography networking idea:

"Think Global at your Local"....

Taking the idea of the TEACHMEET, which is a very successful one from Scotland.

Arrange to meet with other local colleagues in a room at a pub in a central location, hopefully with WIFI and arrange for people to bring short ideas to share with the others. The TEACHMEET model can be adapted in numerous ways...
A few freebies to hand out, and a good time will be had by all (including the designated drivers...)

"See the world through the bottom of a pint glass."

How about invites printed on beer mats ?

I think this idea is 'a goer', and you might see me in a pub near you sometime in the next year....