Regulars at Callahan's include a talking dog, several extraterrestrials and time travelers, an ethical vampire, a couple of Irish mythological beings, and a parrot spewing obscenities.

Irish whiskeys are the preferred beverage, with Tullamore Dew and Bushmills mentioned in nearly every collection of shorts or novel that references the saloon.

The regulars at Lady Sally's brothel (where the employees are "artists" and the patrons are "clients") insist on the same empathy and humor as those at Callahan's, and they are just as likely to have fantastic backgrounds.

In 1997 Legend Entertainment released a graphic adventure game for the PC (Callahan's Crosstime Saloon), designed by Josh Mandel (of Freddy Pharkas: Frontier Pharmacist fame), based on the series.

Included in the game are several songs performed by Spider Robinson himself; these can be heard by talking to the pianist in the bar and asking for "one of your specialties".