I especially love the look when employed to maintain a sense of openness in a room while also injecting some color and contrast. This look is best achieved by using a lighter color on top— white is a lovely safe bet (pictures 1-4, 6-8)— and a darker color on bottom. To break up the contrast place a piece of art (pictures 1, 2, 6) or other object (Nathan Turner's Table top vignette in picture 4, and the lamp in picture 8) so that it overlaps at least a little bit of both colors.
Using a bold color (picture 5) on top can work equally well, especially when paired with a subtler color on bottom.
To achieve the look, check out eHow's instructions here.
I think I may have just discovered my weekend project! What about you, are you digging the look too?
(Images: 1, 7: Les Indiennes, 2: Jake Curtis for House & Garden UK, 3: Mark Lund via The Nest, 4: Miguel Flores-Vianna for Domino of Nathan Turner's Apartment, 5: Domino, 6: Orange Country Register of Nathan Turner's Apartment, 8: Real Simple)