How to QUICKLY flip between 2 monitor configuration.

[Guest]

A user has 2 monitors. Normally the second monitor has the "desktop
extended..." config. for double desktop real estate.

Is there a utility or a configuration profile which would enable the second
monitor to flip-flop between being "desktop extended..." or replicating the
primary monitor.

I need the second monitor's work to be 'remembered'.

I need this so the user can show info to a client on the other side of her
desk.
i.e. she spins the second monitor around, clicks on whatever, and instantly
BOTH monitors show the same info.

 

[DL]

If you use a dedicated multi monitor graphics card its an option/utility of
that cards drivers.
If you use the winxp multi setup, you could try here
http://realtimesoft.com/ultramon/