Let me just admit this right off the bat; I don't use services in Mac OS X. I'll use an Alfred extension or two in order to make my life a little easier but I've never really tried to get services to stick in my workflows.
I'm going to change that.
This article by Kirk McElhearn at Macworld on How to use services in Mac OS X has pushed me over the edge. What are services? McElhearn explains them this way "Simply put, OS X services let you borrow features from other programs."