On Disc 7 (only available on the 8-DVD Limited Edition version), go to the Deleted Scenes Menu. Highlight "Play All" and then press the 'Up' arrow key. The cursor will appear on Sam's arm in the mirror. Press the 'Enter' key and you will be taken to another menu where you have the option to hear commentary for the Deleted Scenes by the characters Sam Wier and Bill Haverchuck (in character).
Reviews: DVD Talk also has a review of
Freaks & Geeks -- Limited Edition Box Set by Randy Miller III.