I picked up my iPhone 5 today and went to Zagg to get an invisible shield put on it. They only had the front shield so I decided not go go that route. I'm going to wait until a full shield comes in and in the mean time I decided to use an extra Galaxy S3 we had at the office (for a couple of days). I went to put the micro SIM from the iPhone 5 into the Micro sim bay for the Galaxy S3 but the iPhone 5 SIM is smaller than your standard micro SIM. The following is what I did to get it to fit anyway.
1) When the regular sized micro SIM is clicked into your Galaxy S3 (securely fastened in there) slide it out by using the top of the SIM that is still (barely) visible. Once it's out you are ready to proceed.
2) Slide your iPhone 5's SIM into place as shown in the picture below. You'll see the old SIM to the right and the tool I used for this process on the left - however you can use any tool to slide the old SIM out and the new SIM in.
3) For extra security I took the original blue tape off of the aluminum SIM container and put a piece of clear scotch tape over it to fasten the iPhone 5 SIM a little more securily.