Although playing ping pong without a paddle isn’t really an option (hands don’t really do the trick), I don’t think that using this new case on your iPhone will do the trick either. However, I have to say that it looks pretty cool anyway.
The Ping Pong Cover from Incase sells for $30 (USD) and you get the choice of black, red, clover, or electric blue. The red and clover colors are best in my opinion, as they really look like ping pong paddles.
If you’re nutty enough to use your iPhone as a paddle, rest assured that the texture is the same as a normal, cheap paddle, so you probable could play with it if you’re really accurate and have a good grip.