The Apple Store itself.
You can always buy it from Apple's home page or you can check out any household electronics store, most of them have iPhone.
You can visit apple.com or visit a local apple store for unlocked iPhone.
You can purchase an iPhone or iPhone 3G at the Apple Retail Store or the local 3 Shops/ATT if you'd liked to. No reservations are needed to be made.
At&t or the apple store (it might be coming to Verizon wireless but not now)
You can buy an iPhone almost anywhere electronics are sold. I recommend you buy one from the Apple Store. You can get from AT&T Mobility, Verizon, O2, T-Mobile, Orange, SFR, Bouygues, Vodafone, Optus, China Unicom and Apple Store.
amazon, apple store, best buy, searching online
From a robber who had his share with an Apple store.
There are many retailers that one can buy a laptop from that is compatible with an iPhone, however, Best Buy and the Apple Store may be the most popular. Best Buy because it specializes in electronics, and the Apple store because they make the product.
You can purchase an iPhone at almost any electronic store such as BestBuy, Target, and Walmart. You can also buy iPhones from your local Apple store.
AT&T Verizon Sprint T-Mobile Walmart best buy apple store
There is a BNSF emulator available for the iPhone. You can find information about this on the Apple website and inside any store that sells Apple such as best buy.