Currently, people are having meetups, but instead of meetups how about we build software which helps assemble smart mobs?
Cellphones, PDAs, Wifi, everything is in place. Now for the software, we need software which can match people of the same political ideology and alert them both when there are other people in the same area of their ideology.
This would allow smart mobs. This would help with meetups greatly as people will be able to approach people offline a lot easier. This kind of software already exists in Japan as dating software, but I think we all know that politics are more important than dating.
So who is willing to try and build a new generation of smart mob social software? A portable friend finder sounds like it could be useful for offline organizing.
The details about how this could be done can be found here http://ttt.media.mit.edu/research/TR-580.pdf