Switching between 3 monitors and Crossfire/SLI?

Hello all, I'm about to build a new system but I can't find the answer to a key question and I'm hoping someone here can help.

I am a programmer, so during the day I use 3 monitors and 2 video cards. What I would like to be able to do with the new system is set it up so that I can switch back and forth between this 3 monitor setup and a single monitor Crossfire/SLI configuration for gaming. Ideally without having to reboot.

Is this possible? I've found some references to ATI's "SurroundView" but everything seems to talk about linking an ATI card to an on-motherboard graphics processor. I'm just looking to put 2 cards in, say 2 4850's, that I can run most of the time in non-Crossfire mode to run the 3 LCDs, but be able to switch on Crossfire and get the high gaming power on my primary monitor.

Any advice appreciated! Thanks in advance.

Brian