Viewsonic have produced a 120Hz LCD monitor prototype:

I'm amazed nobody had done this sooner. When you put a CRT at 120Hz next to a 60Hz LCD the difference is like night and day. Most people don't think you need 120Hz but if they actually saw a direct comparison they'd be amazed by the difference. The motion on the CRT is so smooth it's like wiping your arse with silk.

What's not clear from the press release if if this monitor is like 120Hz LCD televisions which only accept a 60Hz signal and interpolates the other 60 frames. I suspect this might be the case since most manufacturers don't seem to perceive there to be a need to support a 120Hz signal. Hopefully it'll be a true 120Hz monitor and I'll finally be able to get rid of my FW900.