That's a handy tip for keeping things dry. My own fixes usually involve a lot of scrambling for rags when the drip catches me off guard. Your plastic bag idea sounds much more civilized. Next thing you know, the kids will be wrapping the whole pipe in bubble wrap for safety.
My entire toolbox used to be duct tape for every leak (it never held more than a day, honestly). Seeing that plastic bag trick last winter changed my whole outlook on quick fixes, because it actually contains the mess instead of just redirecting it. The bag might look a little silly wrapped around the pipe, but you can leave it for hours while you figure out a real solution. Bubble wrap might be next, though the kids would probably pop it all before it did any good.