My new, favorite place on the web is called 43 folders (not to be confused with 43 things) which is one big Virgo Nerd Central. All sorts of interesting solutions to too much chaos, not enough productivity.

Going through the archives, I found an interesting tip-Vaccuming The Lungs or How To Breathe Deeply When You're Nervous. It goes like this:

1)Exhale everything
2)Bend over at the waist (which gets the last bit of air out) and don't let any new air in
3)Stand up and wait about 10 seconds...by this time your body is craving a nice inhale
4)When you can't stand it anymore, breathe.

As the author says, this "reboots your lungs." and moves you away from nervous breathing.