Just a heads up we do async chat all the time here at my office, but we use Skype instead of Campfire. I don't want anyone to feel like they need to pay a monthly fee to get that service. Skype does persistent chat, you can add people to rooms and they remain persistent as well. You can 'favorite' rooms to keep them sort of pinned in one spot in your list of active convos. It's handy. http://cl.ly/2d3d1M072M1H1h3P1A0…
Both solutions take about 15-20 minutes to set up and cost nothing, provided you have a VPS to host the server on.