I will assume you do not mean the "Slide to Unlock".
Unlocking your phone's cellular plan is probably what you meant. Having your phone unlocked means you have the ability to get cellular service, but without need of a contract. Unlocked iPhones cost $450 more than their contracted counterparts. Your phone also becomes unlocked when your 2 year contract ends. This is why selling your old iPhone after 2 years can actually get you a net profit.
Unless its an iPhone then it would be no.
You can check to see if your iPhone is unlocked by inserting a SIM from a different service provider and try to make a call, if its successful. Your iPhone is unlocked.
yes. once an iphone is universally unlocked it will work.
Yes, you can now buy the iPhone 4S unlocked direct from the Apple website
eBay or Craigslist
There are several providers of unlocking services for iPhones - both on location in Orlando, but if you don't have an unlocked iPhone yet, you could check out unlocked iphones on www.unlockediphones.net.
600
No it has to be unlocked
No!
Yes
Yes, it is possible to buy an iPhone that is unlocked. An unlocked iPhone is not tied to a specific carrier, so you can use it with different mobile networks by inserting a compatible SIM card. You can purchase unlocked iPhones directly from Apple, authorized retailers, or certified refurbished sellers.
Yes, you need an unlocked & Jailbroken iPhone. Which isn't cheap.