Instant Messaging is a neat communication tool. Since your Buddy List will tell you which of your buddies are online, you can "talk" with them instantly anytime you want to.
Here's my reply from PVLD2007:
e20learning (6:31:22 PM): Hello?
Auto Response from PVLD2007 (6:31:24 PM): Congratulations! You have successfully send an Instant Message. Please copy and paste this text into your blog.