According to Engadget, Radio Shack is apparently in the process of dropping the price of the iPhone by $30, latest by tomorrow.
Radio Shack is planning to reduce the cost of AT&T 16GB iPhone 4 to $169.99 i.e. a $30 discount which comes with a two year contract from $199.99. Even the 32 GB model can have a $30 discount at the Radio Shack which also comes at the price of $269.99. The 8GB 3GS price will come down to $19.99.