I use @Agendas fairly extensively. I use the Add-in for Outlook and sync to a palm...
I use a notation similar to the built in waiting for functionality of the add-in. When I create an agenda item I use the following format:
John Smith 05/05/06 Discuss impact of press release on xyz project.
The data is the date I recorded the Agenda next action. The name helps me find the person I'm looking for in palm to do when I filter by the @Agenda category.
I've also created in outlook a custom field "Agenda For" which I fill with the person's name. I have a custom view "@Agenda's" grouped by this field and filtered on the @Agenda category.
I typically have @Agendas for my direct reports and any staff matrixed to me for a project. I keep several for my boss and for the peer managers in my business unit. I also keep agenda items for staff meetings, etc.
When I do a one-on-one I use the @Agendas view (and a similar @Waiting For view) for an agenda.
Seems to work very well for me.