The iPhone launched today on Virgin Mobile, right on schedule. The 8GB iPhone 4 will be sold for $549, while the 16GB iPhone 4S will set you back $649 — steep prices, for sure, but the phone does come without a contract and the usual accompanying subsidy. Plan pricing is the same as we heard earlier — $35 will get you 300 minutes, with unlimited text and data usage. If you need more minutes, the $45 / month plan gives you a whopping 1,200, and $55 will get you unlimited everything. If you're interested, you can buy right now on Virgin Moblle's site — and if you're in Chicago, you'll soon be able to buy the iPhone right in one of Virgin's new retail stores.