Lets you tag/categorise/sort your groups to help you find them again more easily and also lets you quit groups more easily

Lets you add tags to any flickr user, you can then view the tagged users via a whole range of different filters, including view by tag, view tagged users photos,favourites,testimonials,most interesting photos, photos of that user etc, etc

Adds Tags button to add Technorati Tags

Gives 360 tagging functionality