Pandalet:
Aerial work is (from JAR OPS in Plain English)
Where an aircraft is used for specialised services such as agriculture, construction, photography, surveying, observation and patrol, search and rescue, aerial advertising, etc. In other words, not carrying passengers in the normal fare-paying sense, although "essential persons" may be carried, actually up to 6 indispensible people, excluding crew.
"etc" is actually in the JAR OPS definition, so I would suggest that anything you do that is not simply taking passengers from A to B is fair game for not requiring an AOC.
Phil