SEATTLE --In 1989, a few short weeks after the worldwide launch of Nintendo's Game Boy, rival Atari released a handheld game system with a backlit color screen. The engineers at Atari considered Game Boy and its dim, low-resolution monochrome screen to be a technological joke.

So did the engineers who created technologically superior handhelds at Sega, NEC, SNK and Tiger.

But 11 years later, who's left in the handheld game market? Since the release of its first model, Nintendo has sold more than 100 million Game Boys (including Game Boy, Game Boy Pocket, Game Boy Light and Game Boy Color), while all of its challengers have dropped out of the market having barely made even a dent.