As a fan of stars in general, I note with some interest Google’s application of stars in the main search product. This is a pretty big deal. While Google often experiments with stuff on search results pages, a feature doesn’t get promoted unless it makes a positive difference for a lot of users. I bet Google gets a bunch of good user data out of this feature.
Interestingly Google likes stars for the same reasons I do. They’re an extremely lightweight UI mechanism in terms of cognitive load. Stars don’t take up a lot of screen real estate and they’re not hard to operate. Plus, they can easily be ignored by less sophisticated users.
I wish more personalizable information aggregation applications featured stars.