Burning smell after driving, is that an oil leak?

[simondavenport]

Noticed a faint burning smell when I get out of the car after a drive, especially after longer trips. It's not strong but it's definitely there. A friend reckons it could be oil dripping onto something hot, which sounds alarming. I've never seen any drips on the ground though so I'm not sure. I read a piece on spotting an oil leak before it damages your engine and burning smells were mentioned as one of the signs, which made me take it more seriously. Has anyone had this smell and what was it? Could it be something totally unrelated like the clutch or brakes? I'd rather not ignore it if it's a warning sign of something bigger.