Philosophy of tags / Social software

del.icio.us

* stores bookmarks online
* tag bookmarks
* shares bokmarks

flickr

* stores photos online
* tag photos
* shares photos

technorati

* tags blogs

This products let people share and tag personal goals online. They are a way to organise data online, a form of folksonomy (practice of collaborative categorization using freely chosen keywords).

Google already added a tagging feature to My Search History product. Another product that will have tags is Google Base.