I bought think since it explicitly said it would work with the iPhone 4.
While the iPhone does fit (albeit with an odd fit, that seems to leave slack on the screen, but be tight to the sides) the lock button marking is next to the volume controls on the left, and the headphone jack is on the bottom right.
I've not seen an iPhone 4 *or* and iPod Touch with that design (yes, the headphone jack is on the bottom for the touch, but the lock button isn't on the top left). Even if I rotate the phone, so none of the marked areas for controls match, the headphone jack still isn't flush to the hole in the arm band.
Useless to me with my iPhone: no access to controls, using the touch-screen is cumbersome, and there's no way to reach the headphone jack.