Personally, I have used chat – including video chat to communicate with family members. We started using Yahoo’s chat and migrated to Windows Live. I recently chatted with a distant cousin via Facebook. The problem with chat is that you need a partner and you need to agree to use the same tool or a tool such as Meebo that integrates multiple chat engines.
For this project, I installed Meebo on my work computer and had it active for several weeks. Meebo instantly recognized all of my Facebook contacts and would constantly pop up when someone came online. When I was at my desk, I found this to be annoying.
I wasn’t a very effective user of Instant Messaging for professional purposes. Since I’ve seen this suggested as a way to handle reference questions or homework questions, I think this could be a valuable tool once developed.