And now there is a website to ensure that this happens.
For a price, of course.
Like-a-Local.com specializes in hooking tourists up with locals in London, Antwerp, Barcelona, Madrid, Amsterdam, Paris, and Lisbon. Simply mention what you are looking to experience (local restaurants, local architecture, local shopping, local etc.) and your hired local will then do what locals do best: show you around like a local. Get it?
Sounds like a pretty good deal to me.