General:
* Adaptable
* Flexible
* All-purpose
* Multifaceted
* Multitalented
* Polyvalent
* Resourceful
* Variable
More specific:
* For people:
* Multi-skilled
* Well-rounded
* Jack-of-all-trades
* For things:
* Functional
* Practical
* Multi-use
The best synonym will depend on the specific situation and the meaning you want to convey.