Not quite sure if this has been suggested before, so please bear with me.
I know this may be a little early considering that there are still only a few parties around, but it would be nice if we could join more than one. Of course, there would be a limit to how many you join because a party still needs the devotion of its members. Therefore, the limit could be put at perhaps 2 maximum parties that can be joined at the same time [in the near future]?
There are parties popping up as well as party ideas already brewing in the minds of Rescreatu users. It's a difficult choice when you find a new party that catches your interest, but you don't want to leave the other one because you've grown attached to it. I think adding the ability to join another party would also help with the influx of members for the involved parties.
It might be a bit too early for this idea since there are just a few parties around, but I hope it could be given thought to [unless this idea is already in the works]. :)