At the Penny Arcade Expo, North America's largest public games event, the Nintendo DS is as ubiquitous as the cell phone. You can find attendees playing them everywhere - at beanbag lounges, in lines for food, even while sitting down in standing-room concert crowds.

This cross-section of avid gamers - a sharp contrast to the kids-and-moms demographic that Nintendo has staked out since the Wii's rise - has almost unanimously chosen Nintendo's portable as common ground. But it's no surprise that old-school gamers remain fond of Nintendo, even in the era of Nintendogs and Brain Age.

What's more shocking is the other source of common ground among these DS owners: flash carts. They're the iPods of video games, letting DS owners transfer downloaded games and programs from their computers onto their handheld devices. Unlike the iPod, however, there's no official, legal iTunes equivalent for flash carts.

An informal survey of PAX 2008 attendees found one flash cart in every four systems, and while the survey counted only 100 attendees, evidence supports the widespread ownership and use of DS flash carts among hardcore gamers. They're cheap, simple to use, easy to find and able to run almost all DS games.

If gaming history is any indication, this sort of rampant piracy should have doomed the portable system to an early death. Instead the opposite has happened, and surprisingly it's no accident. The story, then, isn't the piracy; it's Nintendo's unique way of dealing with it and the companies left in the cold as a result.

***

DS flash carts are unofficial products, cheaply produced by semi-anonymous developers in Asia. Yet this illicit industry is efficient, pumping out glitch-free products in mass quantities. How'd this happen?

Nintendo's longtime indifference is partly to blame. In the Game Boy Advance era, leftover "development" cartridges from the older Game Boy Color were hacked to work on the newer device. While far from an ideal option - these rigs ran slowly and poorly - they were cheap and simple enough to get the hacking ball rolling.

It didn't take long for enterprising flash cart programmers to work out the kinks. Nevertheless, their product - priced a bit too high, sold by too few distributors - never broke through to the mainstream. With the DS's impending release, these old carts might have merely vanished as a niche interest for hackers and pirates. But somehow the old carts worked fine on the DS. Before long, hackers found a major loophole: The DS could retrieve GBA data from a flash cart, essentially giving hackers a two-year head start. As a result, DS flash carts became sophisticated very quickly.