This morning I was making plans with friends via email, and after reading through our short exchange, I realized I was the only one not to include an email signature. At work, I use a signature that includes my name, title, and email address. I don't include one in my personal email at all (which according to this post on decoding email signatures, makes me cool). Conversely, one of my friends has a super-thorough email signature including full contact information — address, phone number, email — plus her Twitter username, instant message contact information, and link to her Flickr page.
Do you use a signature on your work emails? Personal emails? What does it say?