How do you do your collaborative podfics? Does everyone just record their bits and then someone sticks them together with whatever additional production value adding is desired?

Basically, yes. Although we usually choose to record together because we feel that someone reads this character well and another reads this one well, etc. And we usually beta-listen to each other's contributions, and we discuss the text and the reading, etc.

I'm talking with a fellow podficcer about recording something over Skype, though, where we'll read dialogue together, so we can actually respond to each other in real time.