If you are like me, the most compelling thing about the 3DS that you've seen so far has been the Augmented Reality games that come included with the system. I can't help but wonder what other games and applications could be created like this. In any case, I've had a number of crazy ideas that I'd like to share with you:

• Strategy games on the living room floor: Imagine playing a game of SimCity or Starcraft on your living room floor (or a similar flat surface). You can immediately adjust the camera to any position you want, viewing the environment from any angle.
•  UnReal Tournament: It should be possible to track another player's position and distance through the streetpass functionality (basically you measure the time it takes to receive a signal and the rotation of the device). With this enabled, you can use AR to effectively create a REAL-LIFE deathmatch game.
• Giant Multiplayer Boss Battles: Following the previous idea, imagine teaming up with a number of players to take on a giant boss of some kind that could be composited into the sky in an outside area. You can aim your 3DS upwards and shoot at weak spots all while cooperating with other players.
• Card Games: Seeing how the 3DS uses cards to identify Augmented Reality images, It would be interesting to play cards through the 3DS. Pokemon would be a great way to do this.
• Star Wars Chess: With Augmented Reality, this can finally become a reality. A chess board can finally contain animated characters that can be seen through the 3DS screen.

Hmmmm i was actually not very excited about it as I didn't understand  what possibilities it could have. I think card games would be the most easy to concieve for developers. Games like yu gi oh or magic could benefit greatly from this. :D

Now i dont understand how the AR cards the unreal tournament you describe. Care to elaborate a little more for the ones that lack imagination like me lol

AR Cards are used to tell the system the orientation and distance from where the graphical effects will take place. In this case, they wouldn't be needed.

Instead, the streetpass connection could be used to calculate the distance between players while the motion sensors can communicate the orientation.

It is my assumption that you can measure the distance between systems by measuring the delay between sending and receiving data. Obviously the longer this delay, the farther the distance will be (it takes time for data to travel through the air even if it's milliseconds).

Within this communication, orientation data can be communicated. This can let players know where they are facing in relation to each other.

By pinpointing where other players are, graphical effects can then be painted in those locations, creating the illusion that your friend carrying his 3DS is actually a game character. 

You can use this to create a kind of real-life deathmatch experience, almost like a graphically enhanced version of laser tag. In this manner, you could go to custom locations (your house, parks, malls, etc) and play in a real world location with real players.

It's a crazy idea and I have no idea if any of it would actually work, but it would be interesting nonetheless if it could be made a reality.

Using 3DS wireless would imply a ~10 meter perimeter between all players, other wise connection would be lost.

Obstacles in the "real life arenas" could change dramatically on-screen the actual real the position of a player that is incorrect on the console due to obstacle, and thus signal loss.

It needs GPS service to work properly.

Also, there's already a game for android OS called Wi-Fi Army that works like you say, but on a worlwide scale, and it doesn't have augmented reality characters. Every players playing it at the moment appear on the city map and you just go near them and shoot them you the cellphone camera.

Actually wireless can be used within 100 feet (30 meters) on the 3DS, so it wouldn't be too bad.

It would probably have to be played outside in an open area to limit obstacles that could impair wireless communication (i.e. park, football field, tennis court, etc.).

I haven't played the android game, but the whole point would be to have augmented reality characters and environments surrounding the player, effectively turning the real world environment into a semi gaming world.

In that case you could pass through the augmented reality environments... They're virtual, you could cheat.

I

Look at the sales of eyepet and eye of judgment.

Digimon or pokemon games that read cards and not really require the card to be present in the camera at all times... I don't find the idea of a game that requires you to look at 3 screens (3rd being the one in reality)... 2 is already enough for me it's more of a reader than augmenting reality or maybe you can use it for reality games like a real life treasure hunting by focusing the camera outside of your home, in malls, etc. but besides that I am stumped.

Having seen it first hand, It is my impression that the game needs a fixed point to operate in AR, that is what the card is really there for.

So most of your ideas would not necessarily work.

However they had a flying head game... where you didn't have a fixed point... but that also assumed you had space all arround you (though it did recognize walls and made holes in them).

I would say that your ideas although interesting would be more fitting or a kinect device, well besides the SW chess that could definitely work considering the small surface to "film".

take this with a grain of salt, cause although the card AR game had trouble starting when I moved the 3DS, I didn't try to take it off screen when the game was running... probably should have to see the effects :p