I recently stumbled onto the phenomenon of DVD Easter Eggs and found some for Supernatural. Don't know if they've been discussed before, but I figured I'd post them again.
Supernatural Season 1--
On disc 6, go to the special features. Highlight the Stills Gallery. Jensen's eyes will turn yellow; go left and hit enter to see alternate title sequences.
Also, highlight A Day in the Life of Jensen and Jared. A window in the house in the corner will light up. Go right and hit enter. This will take you to a message from Eric Kripke thanking the fans.
There are several additional Ghostfacers videos. Go to the Mythology section on Disc 6. Go to Paradiso. Highlight Angels and Archangels. Go right and the clouds will light up. Hit enter.
In Purgatario, go to the Bonds of Limbo. Go left and the doors will light up. Hit enter. Also, highlight menu and go left where another door will light up. Hit enter.
In Inferno, go to The Sweet Song of Death and go right. Hit enter.
Anybody know any more?