I can see that as being useful. On the other hand, a voice conversation allows me to talk and work on the actual task at the same time, instead of switching between the task and typing in IM.
wow, quality. I can't wait to have conversations with you.
I don't know if you were being snarky, but the parent post mentioned using IM to collaborate on a task with someone remote and my response was intended as a comment that I'd rather talk to that person while working together on the task than use IM. That way, I can use my ears, voice and keyboard together on the actual task rather than having to spend time typing into the IM client. I did not mean to imply that I wouldn't be paying attention to the caller.
I once spent 6 hours on a conference call with two remote team members working to solve a time-critical software issue for a delivery. Using IM would have been cumber/tiresome and would have probably been much less efficient than voice.