Contrast, your suggestion works for custom rigs but I can't seem to get it to work for a HumanIK rig. I can get one hand to hold an object and the object follows along as expected.

But I cannot for the life of me figure out how to get the other hand to automatically stay attached to the object or follow it.

I've tried parent, point, orientation, etc., constraints using locators, the IK effector itself (wrist) and a few other things. It seems the HumanIK programming keeps a firm hold on the effectors and won't let anything other than the software drive them.

My HumanIK rig is properly setup and its definition locked. Using Maya 2013.

Does anyone know a way to make this work?

Thanks in advance!