Best Buy is offering a free “Side Shield” for the iPhone 4 as of July 28 to anyone who purchased the phone (or will purchase one) from Best Buy.
The clear shield called invisibleSHIELD helps prevent dropped called when the user holds the iPhone 4 by the lower left corner.
All shoppers of the big box store can also buy the shield for $10 or they can get 20 percent off any iPhone case through August 7.
Source: Best Buy