All signs have been pointing to a September release of the iPhone 5, and retail outlets have begun to offer discounts for the iPhone 4 in anticipation of Apple’s upcoming device.

In the US, Radio Shack and Target have already cut prices for the iPhone 4. If you’re not interested in getting Apple’s next generation smartphone this Fall, now would be an excellent time to pick up a new iPhone 4.

US retailers are trying to clear iPhone 4 inventory, with carrier supplies of the iPhone 3GS also tightening. Specifically, Target and Radio Shack are now offering the iPhone 4 at a noticeable discount.

Target has cut the iPhone 4’s retail price to $149 for the 16GB version, and $249 for the 32GB version. That’s a respective discount of $50 on Apple’s most recent iPhone model.

At Radio Shack, the 16GB model if offered for $169.99, while the 32GB iPhone 4 now retails for $269.99. Obviously, picking up your iPhone 4 at Target would result in more savings.

All of the above sales prices include a two year carrier contract with either AT&T or Verizon. You can buy unlocked iPhones on AT&T’s network in the Apple store for the full, unsubsidized price.

Let us know if you choose to pick up an iPhone 4 at one of these discounted rates. Or are you holding off for the iPhone 5?

[TUAW]