While aim/msn etc is a viable option it definately fails in comparision to a mic. When you, or they, are playing multiple tables it just so much easier saying yeah I'm doing this and this because of this, than typing it all out etc. Sometimes hard to type at times while multiplaying but just talking isn't that hard as you are just pretty much thinking outloud.

Try to get a mic if you can (if you don't have one). Alot more people would allow you to sweat them (or vice versa) if you have one imo.