Multipurpose Products

So, we all have them, those little products that do double duty.  Blushers that double as eyeshadows, lipsticks that act as blushers, the lipbalm that also works as a moisturiser or cuticle cream and so on.

However, I think this one takes the biscuit it's the, er ... "personal product" that also works as a hair serum, and heat-styling protector.  Would you?  Could you?

Warning:  while the link is safe for work (it's from HQ Hair) the product itself might not be something you want on your work internet history ... Many thanks to @muddlinleigh for the link!

What are some of your favourite double-duty products?