At 17 minutes you see a cement truck returning to the cement plant. The drum is rotating clockwise. If there was leftover cement it would be dumping on the ground the whole time while driving.
The car in which the friends travel is shown with Pennsylvania license plates in both front and back. Pennsylvania is a state which only issues/requires license plates on the rear of the vehicle.
On the DVD, the opening credits lists Janet Jones (playing Mark's wife Sherry), during the end credits she is listed as Janet Gretzky, her married name.
In the scene at the carnival, it is stated that Chalfont, PA is located one hour west of Philadelphia. Chalfont, PA is located in Bucks County, approximately one hour north of Philadelphia.
During the discussion of "scrudge" songs, Mark asks what song is after U2's "Where the Streets Have No Name." Billy replies with "Bullet the Blue Sky." The order of the songs suggested does not appear on any official U2 album. On The Joshua Tree album, the song after "Where the Streets Have No Name" is "I Still Haven't Found What I'm Looking For." "Bullet the Blue Sky" follows "With or Without You."