I have just purchased a second gtx 670, I was wondering would it be worth me buying a 120hz monitor and would that show more than 60 fps when playing a game etc, it would be better than gaming on a 32" lcd tv which I do at the moment !
No not really. With a GTX 670 SLI setup you would be able to get 60+ fps in most any game but most likely not 120fps at not in the newer games. Do not get me wrong a GTX 670 SLI setup is good I have a Gigabyte GTX 670 SLI setup myself and I run a Surround setup with three Asus 27" monitors and they work very well. Your best bet would be to pick up a good quality 60hz monitor.
I have a 120hz montor and gaming on it is as smooth as butter. If I where you I would go with a 120 if you are willing to pay more than 250$ on a monitor. Even if you get 80+ fps of games I would go for the 120. It also makes upgrading in the future a lot easier because you have the monitor to match your new hardware.
that's kinda lame. even if he couldn't get 120 FPS everything else would be buttery smooth and more fluid. and he will most certainly get more than 60fps which is a boon. 60Hz sucks and you'll know that right away if you go from 120 to 60. kinda like booting from a HD. soon as you start using SSD's you'll know the difference without even having to look.