Ok guys I am new to this forum because I desparately need ASAP. Anyone ever seen "Whose Line is it Anyways?". They do their news game where a guy is in front of a green screen. The guy has no idea what is behind him, but the crowd sees a totally different background and they play this game where the guy tries to figure out what is behind him. I need to replicate that effect and have it implemented within the next 2 weeks so I need some help fast. What I have in mind is my actor in front of a green screen, I film LIVE with a camcorder and feed it into my MacBook Pro via Firewire. Using some type of software and effects (that's where your help comes in) I need to change the background several times as he is talking and acting, and send the changed video out to a second monitor for the crowd to see. Remember all of this has to happen LIVE. Please help with what software can do this, whether it's Final Cut or something third-party. I know it will include chromakey. I have used chromakey myself on PC's in the past but the whole Mac thing is new to me. I am still learning Final Cut Express HD. I just HAVE NO IDEA how to do all of this instantly. Please help!