Best Buy is kicking off a new sale on iPhone and Android smartphones starting this Sunday, May 26. The promotion knocks $50 off the purchase of an iPhone 5, iPhone 4S or iPhone 4 for AT&T, Verizon and Sprint, AllThingsD said. Though, oddly, the iPhone 4 is available for just 99 cents on AT&T with a new two-year contract so we're not sure how the discount will apply there. The iPhone sale will last for four weeks.

Meanwhile, Best Buy is also selling the Verizon DROID DNA for $49 with a new two-year contract, the HTC One X on AT&T for free with a contract and the Galaxy S III on Sprint or AT&T for $49, AllThingsD said. The Android sale lasts just a few days, from Sunday through June 1.

Typically retailers issue sales in an effort to get rid of existing inventory to make way for new models. The Galaxy S4 is replacing the Galaxy S III for example, and the HTC One is the new flagship that replaces the One X. But what about the iPhone? We are of course expecting a new model in the coming months, although perhaps this sale suggests we'll see it before the fall.