You can find the first episode of the SO podcast here. It was conducted over Asterix, open source telephony software that allowed for fancy operations like voice messaging and recording calls!
What would social software look like if we designed them to remove commerce and popularity? Are services like Mightybell an interesting example of where we might be headed?
If you want to build a model of something - say traffic patterns in your town or a hypothetical zombie invasion - you should check out a new project Joel is involved in, Hash.ai.