According to a recent post on 9 to5 Mac, Apple Stores are no longer requiring proof of an AT&T contract in order to purchase an iPhone. The post was supported by Gizmodo, who obtained a copy of an internal memo published on March 22, 2010 outlining the change in policy.

Just speculation, but I can’t help wondering if this is to help clear out back inventory to make room for this year’s rumored new model iPhone….

The new policy still allows purchases of up to five iPhones per day at the discounted, subsidized or upgrade price with contracts.

We called a local Apple Store here in Dallas and confirmed.

Now, if you are in the U.S., anyone can purchase one iPhone per day at the unsubsidized full retail price, up to 10 units per person. Currently, a new iPhone retails for $499-$699 USD, depending on the model.

The iPhones are not unlocked and are still tied to the AT&T network in the U.S. If not being tied to AT&T for a couple of years appeals to you, this may be a good option to purchase or upgrade your iPhone. Of course, the phone would need an unlock to work on another U.S. carrier, such as T-Mobile. Unlocking or “jailbreaking” an iPhone voids its warranty and there’s always the possibility that Apple may close all exploits in the iPhone OS, making future jailbreaks and unlocks impossible.

We we unable to confirm if this is a permanent change of policy or a temporary one, so if you’re on the fence about getting that iPhone 3GS sans contract, this is a good time to check out your local brick-and-mortar Apple Store.