Bought an HD6950, Need advice on desktops

I have a 1440x900 monitor and a 1920x1080 secondary monitor. I have the ATI desktop application. I want to have each monitor display a separate desktop, not an extended one and not a duplicated one. Do you have any advice for this? Thanks!

EDIT: Also note that the 1440 is 17'' and the 1920 is 23''