Hey,
I've released 2 screencasts about Rails + Cappuccino (http://cappuccino.org) : http://bit.ly/CappuccinoRails1 http://bit.ly/CappuccinoRails2
They show how to create a Cappuccino interface for the Rails Weblog Application (by Ryan Bates).
I though I might share it here too.
Best, Thomas.