Allen's non-comics work includes Plexiglas paintings based on pinball machine art, most of which he produced in the late 1970s; and a more recent series of "fake" marine art paintings, which he sells on his website.
In addition to the weekly feature Steven, which ran in college and alternative newspapers from 1977–1994, Allen's comics, gag cartoons, and illustrations have appeared in The New Yorker, BLAB!, Zero Zero, Weirdo, Pictopia, and Duplex Planet Illustrated. In addition to Idiotland, Allen and Leib collaborated on a number of stories in the fund-raising anthology comic Legal Action Comics volume 1, published in 2001.
Along with Leib, Allen was a founding member of the Grammy-nominated band Rubber Rodeo from 1978–1982. Allen has played bass for many other bands as well.
