I didn't hop on board with Photoshop until relatively recently but it's been out there making its mark for two decades now. About.com Graphics Software Guide Sue Chastain has a gallery of Photoshop box shots and screenshots representing the evolution of this popular graphics software.
At Adobe, take a look at the current members of the Photoshop family.
How long have you been using Photoshop?
Since Day Two (Photoshop 1.0), apparently! Lots of geek nostalgia in that picture gallery.