There's nothing new or revolutionary about the games - they retain all of the classic elements. Pong still has the square ball, the Tetris-clone still has the blocks.
it's the interface that makes the difference with these two games. As different as a keyboard or mouse is to a paddle or trackball, they still retain the same basic degree of hand-to-eye co-ordination.
G-sensor technology is different however - especially when you're controlling something displayed on the device you're moving. It's a different skill entirely!
Gravity Pong can be downloaded from FreewarePocketPC.net. The aim is simple - get the ball past the computer controlled opponent's bat. Thisis done by moving your phone - tilting up or down changes the speed of the ball, while tilting to the left or right changes the movement of the bat.
NavTetris meanwhile follows a similar method - move the tetrominoes left or right by tilting the phone in that direction. This title in particular is worth a mention due to it being compatible with standard devices without a g-sensor.