Multiple desktops with xrandr on fluxbox

I use fluxbox.  Sometimes I work with multiple screens, sometimes I don't, sometimes those screen are various resolutions.

To see what screens I have available I run

xrandr -q

from there I can see what screens and what resolutions I have availble.  Then I can configure my setup with appropriately

e.g xrandr --output VGA1 --mode 1680x1050 --left-of LVDS1

Thanks to http://awesome.naquadah.org/wiki/Using_Multiple_Screens for this one.