Can a Canon Flash be used on a Nikon camera?

Complete honest question here. My school has Canon cameras/lenses/flashes and I have a Nikon D60. I know the lenses are not compatible, but are the flashes? What -are- the differences between the flashes. I've asked teachers, but they give a vague answer, or don't answer at all. Is it different wattage on the hotshoe?

Added (1). They usually just answer 'no' or 'no, it'll void the warranty' the vagueness comes into play when I ask why (for why it wouldn't work)

Sure, but not all the proprietary features will work.

If you really need a flash for one of your assignments, you can use the Canon flash in its manual mode using the flash guide number to determine the correct exposure using flash.

Lukily, only Canon has the 6v trigger voltage restriction, so using a Canon flash on your fine D60 will not hurt your camera

It sounds to me, that your instructors are all academics, not working pros or retired pros.

These are the kinds of things instructors need to know if they are to be proficient in teaching photography at any level

They should work in manual mode as I believe the centre pin fires the flash on both systems, however you won't get TTL (auto) flash, as Canon's eTTL and Nikon's iTTL use different signals.

The only time you need to worry about 'trigger voltage' on the hotshoe is if you are using an old fashioned flash (designed to be used with film cameras) on a DSLR. Old flashes had high trigger voltages (10's to 100's volts) whereas modern DSLR's can't tolerate trigger voltages more than about 9V (modern flash units are less than this). If you put an old flash (high voltage) on a DSLR's you'll fry it!

Another option is to use radio triggers - transmitter goes on the hotshoe of the camera & receiver goes on the 'foot' of the flash. Cost about £27 for a set & great at getting flash OFF camera (which is where it should be!). Again, these are compatible between different makes of camera, so easily interchangeable.

Yes. You will still be able to use TTL, but not E-TTL metering.