I use 7.10 with an external monitor and laptop. The standard display tools did not work for me, as they kept stuffing up the resolutions of each monitor, so the best solution I found was to have 2 xorg.conf files, one for 2 monitors and one for just the laptop. I run a script to swap them around when I need to. Not the best solution ... but it works for me. Took me about 4 hours or so to setup, as I've not used linux before.