Since the "Add to favourites" option is gone in version 7 I'm trying to figure out a way to implement similar functionality in the newer version. My idea is to create a custom button on a page that you can see in edit mode. If you click it and publish/save the page you add that page to your favourites (... I have not decided how to store the information yet though).
Does anyone have any experience of this? Or maybe can point me in the right direction?
I guess you would like to create a Widget for the editmode check Ted's blogpost
As for storing the information I would go either with the DDS or the profile data. Karoline has a post on extending the profileData and Ted has another post using DDS.
Hope this will get you started