Actually, the ATI drivers should work now to control your hybrid graphics, as long as you have the very latest download from there site. I have them working for me, and there is a setting to switch between intel and amd there. From what i can tell from how long my battery lasts and the temp report from sensors, it's properly turning the radeon off.
The trick for installing that was to download the drivers, and then get it to build a package for ubuntu ocelot. then install that package, and everything went nice. I'll see if i can dig up the exact guide I used, but I think it was in the Ubuntu docs.
If for some reason fglrx isn't working for you, then you need to use vga_switcheroo.
you need to have the open source 'radeon' drivers active (you can tell via lsmod command).
as long as radeon drivers are loaded and no fglrx drivers are present, vga_switcheroo will exist.
You can google vga_switcheroo radeon and find instructions, the basic principle being to echo "1" into the file which tells the system to turn off power to the card, and then manually unload the radeon module ( usually put in rc.local to automate it on startup).
You should be able to install lm-sensors and then use the command 'sensors' to see both cards listed. If you get -128 degrees for the radeon card's temperature, it's off.
If you go the fglrx route, I've found they combine the sensors, into 1, but generally if its < 50 degrees its just running integrated, if its more the discrete may be on.
