I take it that the "checkmark" option would be controlled from your listing of friends and that, when used, you would be able to deselect categories or types of activity (diggs, comments, submissions, etc.). I'd like to have this--particulary for friends who have a lot of interests, but most their activity is in an area that doesn't interest me.

Unfortunately, some may say that this would be too complicated. Alternatively, there are some categories for which I'm willing to follow the front page but for which I'm not interested in new activity. This could be controlled from the the user options page, with an addtional set of categories and activity types that are desired from friends.