As a mobile phone buyer, I have seen practically every offering from every service provider.  The question I get asked most often is what phone do I carry.  I used to carry the same Samsung, Motorola, or LG phones that my service provider mandated I carry, until I discovered Unlocked Phones.  Due to this discovery, I am walking around with the Nokia 8801 -- a stainless steel slider with Bluetooth and FM Radio that is basically 5 ounces of awesome. 

While unlocked phones are a growing option in the US, there are both advantages and disadvantages.  The biggest disadvantage is that Americans are used to buying the phone with a two-year contract, which means we get phones at a discounted rate.  The same Razr you can get for free with a contract would cost near $140 unlocked.  On the converse, the biggest advantage is that you have the freedom to choose the exact phone and features you want: whether you want a 5 mega-pixel camera or a unique color on a popular phone. 

Most unlocked phone users are like me and maintain the monthly payments for the remainder of my contract.  But the unsung beauty of the unlocked phone is the flexibility of prepaid services.  With the prepaid service you are not commited to a long-term contract and you only pay for minutes you use, and now you can have any the coolest, feature-rich phone which is the major obstacle for anyone considering prepaid.

So the bottom line is if you only pull your phone out of your pocket to make a call, then the traditional models likely suit you best.  But, if you like your mobile phone to be an extension of your personality, you can't seem to find the exact phone you like for your carrier of choice, and you have a few extra dollars to spend it is probably worth the time to look into the wide selection of unlocked phones.