Email signatures are helpful, but not necessary all the time (like do your colleagues really need to know who you are for the umpteenth time?). I streamline my emails by not having a default email signature. When I do send an email to someone who I expect could use the context provided by my signature, I add it in.
Auto text expansion. By attributing _wsig as the trigger, I can type these five characters in my email and up pops this:
Gavan Watson, PhD | Educational Developer, Teaching Support Services
206 Day Hall, University of Guelph, Guelph ON. N1G 2W1.
Phone: +1 (519) 824-4120 x56856 | Fax: +1 (519) 821-8530 | Twitter: @guelphTA | Facebook: TAing at Guelph | Web: http://www.tss.uoguelph.ca/id/ta/
Auto text signatures have the benefit of being program agnostic: I can add the same signature to my work email or my gmail account. Type once, use everywhere.