Idea: user monitoring

[Michael George]

I've been thinking that a framework for monitoring my use of various 
applications would be useful.  I would like to implement something that 
could be useful for the following kinds of use cases:

- Joe has no self-discipline.  He wants to monitor the amount of time he 
spends reading slashdot and playing games, and possibly pop up a notice 
if he's wasting too much time

- Mary's children are only allowed to use the computer for one hour a 
day, unless they are working on a school project.  She wants the desktop 
to enforce these rules.

- Bob loves free software, and is trying to decide what projects to 
donate to.  To help him think of good possibilities, he wants a list of 
all the applications he uses regularly, and how much time he spends 
using them.

I imagine this being implemented as a service which makes an educated 
guess as to what task the user is focusing on, and then records the time 
spent on each task.  There would also be an API that allows applications 
to provide more information (for example, a web browser might say what 
page is being visited (perhaps via a plugin), or an xterm would tell the 
system that the user is really using emacs).  In addition, an API would 
be provided for querying this information, or to be notified when 
certain events occured.

Such a framework would almost certainly need to be desktop-neutral in 
order to monitor all applications, which is why I am proposing it here.

Does anyone have any comments on this idea, especially how I might start 
building such a thing?  It's a little underspecified right now because I 
don't have a good feel for the technologies that would help support it.  
For example, I think this would work really well on top of DBus, but I 
don't know much about DBus.  Any comments would be appreciated.

Thanks
--Mike