Using the current (as of 8/10/12) nVidia drivers (295.71), on openSUSE 11.4 x64, on a Vaio VPCF1 laptop.
Previously, all was working well..until I went to do a presentation, and discovered that the external monitors (both HDMI and VGA), didn't work, and I couldn't switch to them. To get them working, add the following lines to your /etc/X11/xorg.conf file, in the Device section:
VendorName "NVIDIA Corporation"
Option "ConnectedMonitor" "DFP-0,DFP-1,CRT"
Option "CustomEDID" "DFP-0: /proc/acpi/video/NGFX/LCD/EDID"
Option "RegistryDwords" "EnableBrightnessControl=1"
The bolded parts above are what I added, after the nVidia driver installation utility got the new driver out and configured my xorg file. Adding the DFP1 and CRT options enable the external HDMI and VGA ports. This will then let you run the nVidia Xserver Settings program (which gets installed with the driver), and allow you to choose the display(s) you want to use, under the "X Server Display Configuration" option in the left-hand pane. Activate the display, and set it to be twinview, and the monitor will come on.
Best part? You don't have to monkey around with your X config file...the changes are temporary (unless you click the "save to x configuration file" button).
The EnableBrightnessControl option will let the Vaio's FN keys for brightness actually work, and adjust the brightness.
These are only tested on openSUSE 11.4 so far, but SHOULD work on other distros too. Please post here if these things work for you.