It's very easy to log events which happen on one page, e.g. the opening of some js triggered additional information fold-out.
how it works is described e.g. at this site (german):
as the result you can see the on page events in actions/pagetitle as a group of actions for that page => that's great :-)
But it would be even better if you could see these actions directly at the visitor/visitor-log also. Having that you got a complete overview of the behaviour of the visitor at one sight.
Please use this forum for suggesting features: http://forum.piwik.org/list.php?3
and if possible post screenshots showing what you mean / request. cheers