What are the advantages of unlocking my phone?
The biggest advantage of getting your phone unlocked is choice. With your phone unlocked you can swap SIM cards at different times to get the best value of the different tariffs from the providers, you can choose which network and which tariff you want at various times.
Mobile phones which are unlocked tend to have a greater second hand value, the value of your handset could be increased. Many people will unlock their mobiles so they can use a local prepaid SIM card when in a different country instead of using the costly 'roaming' feature provided by their current network provider.