Forwarded to me:

The longer your e-mail signature, the lower down the food chain you are.

Some people put a whole novel in their sig:

Their full name, including "Jr." or "Sr."
Job title, which generally includes both the words "deputy" and assistant.
Streetmail address with mail stop.
Business phone number, with different versions for people dialing from the internal corporate PBX vs. people dialing from outside.
E-mail address. 'Cuz it's not like it's in the "From:" line of every e-mail or anything.
And finish it off with an inspirational quote from Battlestar Galactica.
If that's a description of your signature, then you're a flunky. Time for a Starbucks run, Commander Starbuck.

Some people include signoffs like "Cheers!" and "Thanks!" and "Best!"; others don't bother.

I never gave that one any thought until the New York Times analyzed signoffs and determined that a brisk signoff is tantamount to a brushoff.

This is something else for me to feel self-conscious about. Thanks, New York Times.

Some people's signatures are way too long.

One of my colleagues - actually one of my favorite people in this company, so I'll avoid naming him here - has a twenty-one line e-mail signature, which includes:

his name
title
Streetmail address
Three instant message IDs
E-mail
URLs for two sites he edits
Second Life avatar name
Name of the location of his office in Second Life
And the office's Second Life co-ordinates, or "SLURL."
Contrary to my earlier observation, this person is actually not a flunky; he has an important position. Wish somebody could get him to slim down his 800-pound e-mail signature.

What should people put in their e-mail signatures? What do you have in yours? Let us know.