Nintendo has been testing some of the interactive possibilities of the DS over the past couple of months at, of all things, Seattle Mariners games. Yes, the Japanese-cum-Pacific Northwest videogaming giant has been testing live event functionality by allowing fans to download live broadcasts of the game on the field, watch replays, get stats, and more. It's called the Nintendo Fan Network, and it's been available in Seattle since the beginning of the season.
The coolest thing, however, that you can do with your Nintendo DS at a baseball game, is order food and drink, pay for it, and have it delivered to your seat, tip included. That way, you can enjoy the game and still be able to get all of the hot dogs and beer you can handle. Now, when Nintendo adds the ability to go to the bathroom to the package, it will have perfected the live event experience.
Physorg.com: Nintendo Tests Interactive Fan Network