The Best Way to Protect iPhone 4S Screen?

these days, i just wonder if i need to buy a screen protector for my iPhone 4S, i am just afraid it will be scrached or damaged by something, i just want to know what i should do for this, can you guys give some advices on this matter?

Loverain: I take it-from your question-that you are using your Verison/ATT  4S with T Mobile..right?
Did everything "transfer" alright? Sure would like to do the same.