RadioShack stores are now reportedly taking preorders for the iPhone 4S, and can offer customers a discount of up to $200 via the chain’s “Trade & Save” program.

In the U.S., AT&T, Verizon and Sprint might have sold out of iPhone 4S preorders (with the Apple Online Store shipping the handset in a lousy one to two weeks), but that doesn’t mean there’s no way Apple fans can preorder a handset for tomorrow’s launch. According to Cult of Mac, RadioShack stores are allowing customers to preorder the recently announced handset right now, and will even offer a hearty discount if you trade in your old iPhone.

Apparently, when trading in an “acceptable” iPhone 3GS or iPhone 4, customers will receive at least $100 off a new iPhone 4S. However, Cult of Mac notes that customers can save as much as $200.

If you haven’t yet preordered an iPhone 4S but want to grab one tomorrow, this may be an option for you. Let us know your game plan in the comments below.