Are all micro sim cards the same?

I have a Samsung Galaxy S3 and I want to use it with Straight Talk. Straight Talk sent me a full sized sim, and I need the micro sim.
I found some sim cutters on Amazon that claim they work for the iPhone 4s, and I was wondering if all micro sims were the same.
Will the cutter work for the s3?
http://www.amazon.com/...004I58ZVY/

I took a look at the link you've posted. Even if all micro SIM cards are the same, I doubt if it will work perfect for your Galaxy s3.