self-service

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Being a retail commercial enterprise or a service in which the customers or users help themselves.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun the practice of serving oneself, usually when purchasing items
• adjective Describing an establishment where the customer is not waited on.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective of or denoting an establishment (a restaurant or shop etc.) where customers serve themselves
• noun the practice of serving yourself (as in a grocery or cafeteria)