Sprint has started accepting pre-orders for the 8GB iPhone 4 model that Apple announced on Tuesday. Pre-orders for the iPhone 4S start tomorrow on AT&T, Verizon, and Sprint.

Apple announced that the iPhone would be coming to Sprint at its “Let’s Talk iPhone” event, and Sprint is differentiating itself from AT&T and Verizon by offering unlimited data for new customers…

You can visit Sprint’s website right now to pre-order the 8GB iPhone 4 for $99. The iPhone 4S will be available for pre-order on all carriers at 12:01 AM PST on Friday. All of the main 4S features are displayed proudly on Sprint’s website.

The 16GB iPhone 4S will be offered for $199.99, while the 32GB version will be sold for $299.99. A 64GB option will also be offered for $399.99.

While Sprint is offering an unlimited data option, it’s clear that an unlimited plan won’t be offered to customers for very long. If potential iPhone customers on Sprint want unlimited data, it would be wiser to buy sooner rather than later.