How do you say goodbye?

I use Instant Messengers, several of them, even though I don't like shortcuts and acronyms by nature. Luckily, I type fast.

But there are some funny social aspects to it that suggest that it's a technology in its infancy. Take the issue of "saying goodbye".... There is no convention for this yet on IM. I do it differently with each individual, as you probably do as well.

"See ya."
"OK. Bye."
"Have a good evening."
"Thanks, you too."
"Talk to you tomorrow."
"Definitely."
"Thanks for IM'ing me."
"Glad you were there."
"Bye."
"ttfn"

And still both of you leave the window open, pushed to the side a little, to avoid the dreaded "Glenn has left the chat", which seems a little cold and almost insulting.

Imagine a telephone call where neither party is quite sure when the conversation is over. You say your goodbyes, listen a little to see if the other person is really done, say goodbye a few more times, then gently lay the phone down on your table and wait for a half hour or so, and if it stays quiet, you hang it up.

That's what IM is like, and it's just weird. One friend of mine draws a horizontal line with dashes ------------------ as if to say "don't you dare type past this line." Another friend writes "VCD" (for 'via con dios'). Doesn't that mean "goodbye forever?" I'm not quite sure :)

So we fumble along, inventing our own solutions. If you have a suggestion for how this is supposed to be done, or if you think this is already solved and I'm just missing something, add a comment....