These are the postage stamp images created for the earliest version of Literary Kicks in the mid 1990s. The "Beatnik series" (the first eight stamps) were created by Levi Asher. The Bukowski was created by Michael McCullough and the d.a. levy is the work of W. Luther Jett.
Over the years, these images have often been shared and sometimes been mistaken for real postage stamps. The best story I've heard about this came from a friend who visited Gregory Corso at his apartment before he died in 2001. A few friends were around Gregory's place, and at one point Gregory produced a printout of the Gregory Corso stamp and told his friends: "Look! I'm on a stamp in Italy!".
My friend says he later took Gregory aside: "you know those postage stamps aren't real". Gregory responded, "I know that, but they don't".
This story gives me endless pleasure. Here are the stamps.