You really don't need four displays and four webcams at each table. People could bring their own laptops and digital video cameras, which they could network with the CPU in the middle of their table.

A live feed--video and sound--of each panel discussion to the networked CPUs might be fun. Partiers could watch the panel discussions on their notebooks or tablet PCs. Or partiers could film panels with cameras they brought themselves.

Available funds, volunteer expertise and labor will limit the imagination, needless to say.