Griffin’s original AirCurve, the amplifier that docks and increases the iPod/iPhone’s volume has now been updated for the iPhone 4 and it increases music by 10dB louder. It doesn’t sit the iPhone in the docked position, instead it just rests inside.

It also now has a metal kickstand for holding it vertically or horizontally. You’ll also be glad to know that the price hasn’t changed either as it will cost you just $20.