I am not That Blogger....
For perhaps the first time in blogging history, the "I'm so sorry I haven't blogged more often" post is actually being followed up with a timely post!
Anyways, on to the homework. I've used instant messaging at work for years. I've found it to be a great tool for working with people who aren't physically close to me. The kind of question where you'd just stop by someone's desk can be accomplished with chat.
But, you also have to be careful with it. It can increase interruptions if you try to answer everything that everyone asks all the time. That also means you need to remember to ask people if they have a minute, before you take over their time with your chat.
At a previous job, someone who sat 10 feet away from me would chat with me via instant messaging. I found that to be a bit excessive. When you can communicate face to face, that is always better. But, when someone is on the other side of the bulding, campus, or world - chat brings us all closer together. Awww....