This hotshoe adapter is very versatile.  It can be used as a "Camera" hotshoe sync adapter or "Flash" hotshoe to sync adapter.  It has a screwlock PC sync port that accepts a common male PC connector or the screwlock PC connector.

It can also be used to connect a Pocket Wizard, Skyport, or other radio slave, and still mount an on camera flash, for cameras that do not have a chassis mount PC connector (like a Canon 300D, XT, XTi, etc., or the Nikon D40, D50, D70, D80, D90etc.).  Note that the camera mounted flash would be limited to manual mode.

Price: $18.50 + shipping