According to RadioShack's official Twitter page, the company will carry the iPhone 4 on its June 24th launch day. In fact, the company will begin taking pre-orders next Tuesday (June 15th) according to a second tweet from the company.
Here's the first tweet, confirming that they will carry the product:
YES! RadioShack will have #iPhone4 at launch. More info tomorrow.
The second came in later saying:
JUST IN: #iPhone4 pre-orders start next Tuesday @RadioShack… and that's only the beginning. RT!
And a final tweet from the company specified the date:
Yep… and pre-orders start 6/15.
Looks like one more place to pick up your iPhone 4, especially nice for those who don't live near an Apple Store.