After lots of buzz over the past couple of days, Apple put to rest whether an “unlocked” version of its iPhone 4 would become available to the US market – by putting it up for sale on the Apple store’s website Tuesday morning.

The unlocked iPhone is available through the Apple store starting at $649. This is the first time an unlocked version is available in the U.S., meaning that owners don’t have to lock into a contract with a carrier.

“If you don’t want a multiyear service contract or if you prefer to use a local carrier when traveling abroad, the unlocked iPhone 4 is the best choice. It arrives without a micro-SIM card, so you’ll need an active micro-SIM card from any supported GSM carrier worldwide,” reads the description on the Apple store’s website.

According to Apple, the unlocked iPhone 4 requires an active micro-SIM card that users obtain from a supported GSM wireless carrier. To complete set-up, the owner then inserts the micro-SIM card into the slot on his or her iPhone, connects to a Mac or PC using the USB cable, and launches iTunes.

A micro-SIM card is a small memory card used in the iPhone 4 and other cellular devices that stores the owner’s wireless account information, Apple said. With an unlocked iPhone, owners have to obtain a micro-SIM card directly from a GSM carrier.

“Apart from AT&T, the only national U.S. carrier that’s compatible with the phone is T-Mobile USA, and it can provide only phone calls and low data speeds,” according to an Associated Press report.

Many overseas carriers are compatible with the phone, so international travelers can avoid AT&T’s international roaming fees by switching out their U.S. SIM card with one from the local country, the report said.

As TechZone reported June 13, industry rumorist “Chronic Wire” leaked the intel on Twitter earlier this week, tweeting: “Unlocked iPhones headed to Apple Stores for Wednesday: MC603 (16GB, Black), MC604 (16GB, White), MC605 (32GB, Black) MC606 (32GB, White)”.

Chronic Wire said the unlocked version would become available Wednesday. Apple surprised us one day early.

Erin Harrison is Executive Editor, Strategic Initiatives, for TMC, where she oversees the company's strategic editorial initiatives, including the launch of several new print and online initiatives. She plays an active role in the print publications and TechZone360, covering IP communications, information technology and other related topics. To read more of Erin's articles, please visit her columnist page.

Edited by Jennifer Russell