Either Whitelabs or Wyyest has a youtube video (I'm behind a work firewall, and can't find it for you!) where they test the viability of pure O2 and just shaking the keg. If I remember correctly, it was 90 seconds of pure O2 infusion and about 15 minutes of shaking to get to the proper PPM for optimum yeast health.
Primary #1 - Midnight Ryeder (Midnight Wheat and Rye)
Primary #2 - Florida Weiss
Primary #3 - Kane-DOH APA (Honey Citra APA)
Secondary #1 - Downtown Flanders Brown (brewed August 2012)
Keg #1 - Raspberry Florida Weiss
Keg #2 - Cinnamon Raisin Cider
Keg #3 - NONE!
Bottled - NONE!