Mac Pro to external monitor

My buddy has a mac pro with the dual monitor set-up, the thing is he needs to connect to an external monitor as well - how can he use his dual monitors to edit and have an a/v out to display it on a tv screen?

Thanks for any help!

-= Jonah

It could be done, does the tv have dvi? hdmi? s-video? conponent?

Well since this is a professional set-up request, you will need professional gear. You will need some kind of DV, HDV, or HD deck to use as a pass through from the editing program (final cut, avid, etc.) or a capture card. IF you have either, just plug the tv into the capture card/ deck, and you will be able to turn external video on in your NLE and then it should just show up as external video.

Tv has S-video and standard A/V it's a bit old but it gets the job done... I'm not sure I understand the response he needs to output the video from the computer to the television. Wouldn't the deck be a strictly internal device?

His Dvi ports are filled due to the dual monitors - is there any sort of firewire or usb device that would allow him to send an a/v signal out to the tv?

Sorry if I misunderstood anything, I really appreciate the help!