Can you switch your OS from a larger HD to a smaller SSD?

I was not sure where to post this so I figured I would try a couple of different places and see what I can find. Ok so I have a 5900 RPM 1T Hard drive currently running my O.S and a few other programs, but it has gotten to the point where I would like to speed up the boot time and running certain applications. I wam looking at getting a SSD that at most will have 124GB of storrage space.

I tried ghosting one hard drive to a smaller faster hard drive on my laptop so I know that it won't work but I have heard some people talking that their is a way to make the computer think that all the free space on the hard drive is gone and the hard drive is only as big as how much space is actually taken up.

Basically I have 2 questions. One can anybody walk me through how to do this and two if I do this will it let me ghost my OS to the smaller drive?