I live on the computer. I work as a Software Engineer and I play PC games. Some of my friends still don't understand how I can have a bad day at work and turn to the PC at home to relax (hey, venting frustrations on pixels is very therapeutic!). However, I can unplug. I'll go hiking, camping, or just out, and the computer stays at home.
So it was really funny to me to talk to one of my friends who's addicted to his Treo. Saw him up on IM this morning;
Me: What's got you online so early?
Him: I am driving now. Talk later.
Oh man. Time to cut the cord. :) Scares me enough when the other driver forgets cars exist because their phone conversation is more important than driving safely. Imagine having to let go to answer an IM!
Edit: Interesting. To save time the Treo offers users the ability, at least through VeriChat, to slam out a quick message in a few keystrokes. Similar to an away messge he tells me. Be simpler, imo, if it offered an away mode when your driving.