On Disc Two, go to the 'Select Episodes' screen and select 'Tests and Breasts.' Go into the 'Audio Setup' screen, and let the background music play all the way to the end (approximately 30 seconds). As soon as the music finishes and you hear a character speak a line from the episode, a large white M will appear on Bill's hat. Select it to see a 3-minute long take of a deleted scene in which Sam just can't keep from laughing.
It's not the funniest thing in the world, but it's slightly amusing.
Reviews: DVD Talk also has a review of
Freaks & Geeks -- Limited Edition Box Set by Randy Miller III.