Okay, not a real Churchill quote but pretty funny. Here's the Churchill Centre's "Famous Quotations and Stories".
In addition to the false quote above there are hundreds of others that can be debunked using the Centre's 2.5 million word database. (the guy just couldn't shut up)
Churchill Centre homepage
Here are a couple they've gathered at the "Falsely Attributed" page:
"If you're not a liberal when you're 25, you have no heart. If you're not a conservative by the time you're 35, you have no brain."
"You make a living by what you get; you make a life by what you give."On a more reflective note, if it weren't for Churchill the Downfall parodies wouldn't be nearly as funny.