
Tattoos R Us — When I Was A Kid, We Bought Mini Football Helmets From Vending Machines (Always Hoping For, But Never Getting, The Jets)
Now, kids can get tramp stamps.
Thanks to cockeyed.com — via current — for this one:
In a Sacramento-area Toys R Us, your daughter can emulate mommy’s ugly lower back tattoo for just a few quarters.

Lower back tattoos are 50 cents each, tucked in between the Hannah Montana stickers and the Mickey Mouse Clubhouse stickers. You can choose a butterfly, roses, a fairy, or other tasteful designs.
Bring exact change, just like you might use for the cigarette vending machine or that one in the truckstop restroom.
Nice find, cockeyed.com

Aha - the Tramp Stamp Machine you were referring to.