Even if you don't care about urban design, you may want to check out this gorgeously presented solution for intersections which support both cars and bicycles.
Protected Intersections For Bicyclists from Nick Falbo on Vimeo.
Though now it has me wondering about car/bicycle roundabouts, as I am a fan of roundabouts as an alternative to intersections with lights or stop signs. (Update: An experiment in the UK.)
And I want systems of cunning bollards and low barriers to help partition the space, as in Rio de Janeiro.
More at ProtectedIntersection.com.
Update: This video got picked up in a collection of sexy bicycle-oriented urban design ideas at io9.