Trey rollerbladed around the venue, out in the crowd, with a wireless guitar during Weekapaug 9-28-91.
Macaroni and cheese: Boxes were distributed to the audience at the 9/28/85 Slade Hall show and at the 5-27-94 Warfield show, and shaken en masse as percussion during "Possum".
Fireworks: First 7-3-94 at the Old Orchard Beach Ballpark in Maine during "Antelope" (thanks Allan Abrams), then during the encores on 8-16-96 and 8-16-97 (the first nights of the The Clifford Ball and The Great Went). The band also played along to fireworks at 10-22-94. (They were not Phish's fireworks, but were from a Disney anniversary party a few blocks away. They started during Julius, and Phish did an extended Julius jam.) They also played along with nearby fireworks during the Antelope at the '93 IC Light show.