Today, it's clear that the industry's most prominent handheld devices don't necessarily appeal to the same audiences. Sony bills the PlayStation Portable as a "hardcore" device, Nintendo markets the DS toward a larger audience, and Apple seems to do both with the iPhone . But things weren't always this way.

Back in the '90s, the Sega Game Gear and the Nintendo Game Boy appealed to identical demographics -- as their names might imply. With so much commercial overlap, it was difficult to deny the tension between the two products. So what did Sega do? Insult their competitor's customer base, of course!