I stumbled across a site featuring the work of a handful of innovators in Switzerland. They have a small list of playable projects, some of which can be downloaded to your DS (if your DS is equipped for homebrew games) Their site: www.and-or.ch.
If you've kept a keen eye on the "games I'm playing" section of my blog, you would have noticed that I added Wardive to the queue. What's unique about Wardive, is that it uses the DS's wifi capabilities to scan the air around the player. Based on the number, and strength of the local wireless lan hotspots, different numbers, and strengths of enemies appear.
The game itself is nothing more than pointing and clicking on the enemies using the DS touch screen, but the concept and the technology behind it is worth mentioning. Combining real world factors and digital world rules together is a new type of gameplay experience that I hope to create in future games. But I won't get into that now. We're knee deep in GuitaRPG.