There's a discussion on the Capita Forums about using Google Analytics to monitor unique hits by adding a web part to the parents home page.

No-one from Capita has popped into the thread yet, but I'd guess all the schools with hosted SLG using Google Analytics would have interesting effects on performance.

I would post a link, but you know what their forum does to links.

Schools forums --> Learning Gateway --> (31718) --> HOW TO MONITOR PARENT USAGE OF HOSTED SLG!

Usual warnings about not taking responsibility if iguanas invade your school.