Is there a way to use Canon 18-200 EF-s lens on Canon 6D full frame body?

I just purchased Canon 6D (Full frame camera) and I hate to lose the usage of my simple 18-200 EF-S lens. Any idea if there is a technology that allows me to use the lens on the 5d body?

Answer

Is it possible? Yes. You can probably do this by physically modifying the lens.

Is it safe? No. The rear element of some (most?) Canon EF-S lenses extends into the body when at the wide (18mm) end. This causes the mirror to hit the back of the lens, potentially damaging both the lens and the camera.

People have had success modifying EF-S lenses to fit on APS-H (NOT full-frame) bodies such as the 1D series, though the lens may not be safe to use at all focal lengths.

PS: You might be able to use it if you find an appropriate extension tube, but you'll lose infinity focus. As far as I know, modifying the lens or using an extension tube are the only two ways.