My signature (both at work and for personal mail) has been very simple for 5 years: my initials. Sometimes I say things like "Thanks" or "Regards" out of respect, or just "Later" to be friendly. I see no need to put your title, company name, phone number, or any of that other stuff. That's what your biz card is for, or if somebody wants to know they can ask. Most of the time, they don't need to know, don't care to know, or already know. So it is just a waste. The only reason to have a signature at all is to mark the end of your message. I guess you could use an inspiring quote though. Like I do on TFP.
