Many times on project calls, activities and action items get identified as needed. I find that a lot of times either there is no date assigned to close these or the dates that get assigned just come and go. Therefore, one effective strategy that I use is to put a meeting on the calendar as a date from which to work towards. This way, the expectation is set with team members assigned to the action that there is a meeting where an update on the action is required.
As Project Managers, it is our job to ensure that work progresses and that actions get completed. Rather than chasing down people or assuming that the item will close itself, a quick meeting is a good way to (1) remind people that something is due and (2) have something to work towards.