In our rules we can then go:
CrudMode(this == CrudMode.CREATE)
The second way we use it (and this one I don't like so much) is that our validation aspect runs both before and after a method (PRE and POST). We use an agenda-group to to indicate which phase a rule should be included which works fine, however we were finding that some conditions were relatively expensive which had performance implications. Our solution was to also include a ValidationPhase enum as a fact and use that to short-circuit the rules. I reckon there is probably a better way to achieve this however we didn't spend a lot of time thinking about it.
cheers
Steve