i not sure if i ask at right place or not, i refer to apple online store Singapore one, i saw that "When you purchase your iPhone from the Apple Online Store, you’ll get it unlocked.", what mean unlocked ? it mean it not contract based and can sign up for service with the  any carrier only right?

any other diff between contract and unlocked? and it apple iphone 3gs only or also include iphone 4?

You can do it yourself easily

This is my answer to several who PM me about how to cut the card : you just need a sharp scissors and a piece of paper

First get the size of the card ; put a piece of paper inside the simcard slot - slightly pressed along the edges to get a impression. Cut the paper to have the size. Put paper on top of the simcard and use a pencil to trace the size on the card. What I did I cut first the right handside close to the gold edge. Then I trim the rest - it is alright to trim off slightly the top n bottoms of the gold edges. The important area is the centre part where you see 2 lines

I have cut so far 5 cards : Digi, celcom, hotlink all works perfectly without any issues