How can I calm down at work?

I’m usually a pretty laid-back, easy-going guy. However, my day job is tech support.

I like the job well enough, I work with friendly, intelligent people in a nice environment, and once the first half of my shift is over, the second half usually gives me plenty of time to read, surf the internet, things like that.

The problem is that I get infuriated during a lot of my calls. I sound pleasant over the phone, but all too often I’m grinding my teeth, clenching my fist and destroying the homemade voodoo doll.

I’d like to be a bit more zen while on the phone. Any ideas on what I can do to keep myself calm while trying to talk Cletus McStupid through typing in a password?