Vent my frustration in a Counter-Strike deathmatch server, Calm down by listening to music or just hitting the Stumble button on firefox. Or go lay down infront of the heater and pop something on TV
For relaxing, I actually practice progressive muscle relaxation. It only takes about 15 solid minutes to relax myself completely!
Sleeping, watching the tv or working out all help me relax and for different reasons. I find that if I go for a run or swim I often feel a lot better if I am stressed about life or work.