Noticing that the count for visitors on sites is always higher than the count shown in Google Analytics live view. For example I have a site where right now the mojo feature says 7 visitors, GA says 1 person on the site (me!).  Is there some lag in the counter in the mojo feature?

Thanks Joe that makes sense, and explains the odd figures. I wonder whether the feature could be made more accurate and "real-time" by adding something similar to GA tracking code within the mojo site itself.  As an option that could be set for the site (and perhaps overridden for each page?),  there could be some JS included in the skin that calls a handler within the site when a page is accessed by a real user (with JS enabled). The handler could write to the database (e.g. a mp_current_users table), and the "who's on" feature could poll the table on a timer.