One day earlier than was predicted, Apple has finally offered consumers the ability to purchase an unlocked iPhone 4 in the United States. At the moment only the GSM variety is available but you’re free to choose it in either white or black styling and in 16GB or 32GB variety.

Regardless of the color you choose, the iPhone 4 in 16GB variety starts at $649, whilst the 32GB is $749. It doesn’t come with a micro-SIM card so you’ll need to activate one yourself from any supported GSM carrier (worldwide). Whether you plan on using an iPhone extensively overseas or just on an alternative carrier, the unlocked iPhone may be your best choice – at least if you don’t want to go down the jailbreak and unlocking road.

You can purchase an unlocked iPhone 4 from the Apple online store here, and it is expected that Apple retailer stores will have them on sale from today or possibly tomorrow – we will update when we know for sure.