Moose at Play's Laser Hockey DS is an adaptation of the best game on Wii Play (that isn't about adorable hopping cows), Laser Hockey. But, you know, on the DS. The neon-light visual theme of the original stays, but the view has been rotated 90 degrees to accommodate the DS's aspect ratio. Right now it's a total work-in-progress, with no variation in ball speed or paddle rotation, and frequent occurrences of the ball just passing right through the paddle.
But none of that really matters, because as of version 0.3.4, Laser Hockey DS has wireless multiplayer. You and a friend can both lase and hock together, and it's free. If the base gameplay continues to be tweaked, this will be a must-have for any flash card.