Steve Jobs dislikes buttons, which is why one of the most premier gaming devices in the world has no tactile feedback whatsoever. But there's still a call for finding buttons on the screen by feel alone, and Tactile+Plus is designed to let you do just that. It's a little plastic sticker sheet that you can place on your iPhone or iPod touch's touchscreen, and it will provide touchable, raised bumps where buttons go in certain games. Just peel the buttons (you get a D-pad sticker and four buttons with the pack) off of the sheet, place them onscreen where the virtual controls are, and voila, you've got bumps that let you know what to press.
The product is made in Japan, but there is a US price listed of $7.40, so you can order it (though it'll be at your own risk). Plus, it seems a little messy -- if the buttons really are sticky enough to stay on the glass, they might leave residue there, and if they're not, they might be tough to actually control games with. But it's an interesting idea, and until Steve and Apple work out that dynamic tactile interface, it might be a workable solution.