It's funny - looking through Google people from many areas of England and Scotland seem to think that this a phrase peculiar to their region. But it obviously isn't by the number of different areas which think so.
Before looking I would have say that this was a particularly Scouse saying- because that's where I'm from.
I'm from Yorkshire and I would use this phrase but my partner who'se from Lincolnshire, just a few miles away the other side of the River Humber doesn't know it and thought it meant a man's erection!!!