If you need to keep track of multiple employees/partners/etc. Areas of Responsibility, you could use the company org chart and list under each one the hats they wear.
If you need to keep track of "Delegated Projects", you could keep an @Delegated_Projects list (or folder). (If you trust the person you're delegating to doesn't need to be nduged, you don't need to track specific actions for each one. If you need to keep tabs on specifics, you could keep it in the notes area.)