I use a similar system to the one db posted, but with a few changes.  First, I abandoned the pulleys on the top rope.  I use heavy duty carabiners.  I know there is way more friction this way, but I got tired of stringing everything through the pulleys.  With the biners, I just snap the line through and go.  I still use a pulley at the pack, though.  For the "lifting" rope, I just use some braided nylon cord.

-pm