Pentax K-x lens compatibility?

I understand that I can use older pentax lenses for my K-x, I'm trying to find information on whether or not I can use other lenses ex. Nikon and/or Canon lenses with my camera.

Information with a source would be greatly appreciated.

The Pentax K-x uses the same auto focus K-mount lenses as does the Pentax 35 mm cameras

You can't use Nikon or Canon lenses with this camera and be able to use the auto-focus or Pentex metering system. Any adapter you may find will be strictly a manual mode operation and some adapters will not allow you to even use the internal meter of the camera

As a general rule to follow, use Nikkor lenses on Nikon's, Canon's on Canon's, Pentax on Pentax and Sony or Minolta on Sony's

The advantage of Pentax over all other camera brands is that all its lenses are forward compatible - even the old M42 screw with an adaptor. However, bear in mind that the older the lens, the less automatic functions you will be able to use.