I just went live with my site a few days ago, and love the real-time capabilities of WassUp. I just wish it had a way of looking at past visits by specific users.
I use the Your Members plugin to restrict certain pages of my site to registered users, basically it's a lead capture system. Right now to see what a given user has been up to I search on the URL of the registration page and hope their username is something I can connect to one of the names of people that registered around that time.
What I'd love (and be willing to pay for) would be some means of viewing/producing a report showing activity by user.