Re:One thing I haven't succumbed to ... (Score 5, Insightful)

Where I work, we use IM quite a lot. Both locally and overseas.

In the overseas case, it's often easier to understand folks via typed English so it's better than using the phone while still being more immediate than email.

In the local case, IM works well because

1. It's not as disruptive as a phone call. You don't have to answer a newly initiated conversation immediately if you're really busy (or just set your client to give a busy message).
2. It's faster than email when the person is there, but if you see that they're away, then you can fall back to sending email (the IM version of the answering machine message).
3. Unlike email, IM doesn't clutter your Inbox and Sent folders with myriad little messages resulting in a long thread to get rid of. IM's transient nature is an important feature so it's best used for communication of transient information, ideas, requests, etc. Of course you can always save the conversation if you need to keep it.

IM falls nicely between the telephone and email.