Should be also possible with Ezedia on PC/Mac or with CubicConnector on MAC. Maybe also with VRWorx (there was a thread on andrew's forum of PanoCube).
Also Golive has an editor for Quicktime, but I'don't know if you are able to set hotspots.
Ask for this feature in the Quicktime list:
http://www.lists.apple.com/mailman/listinfo/quicktime-vr