Identifying stale assignments for cleanup?

Hey All,

<View 4.6>

Is there a way to check in the View Console to see when a user last logged on?  (Besides the Events Tab?)

I am trying to figure out the best way to clean up stale user assignments in our dedicated pools.  (For example, a user leaves the company and I want to free up their VM).

I imagine if there was a "last logon" attribute, something could be done in PowerCLI.

If there was simply a tab in the Console, that would be even easier (but I don't see one).

Thanks
Drew