Steve
I am currently doing the Google rounds on existing (mob) tagging workshops in order to prepare for our workshop/paper and I came across steve - Social Terminology Enhancement through Vernacular Engagement.[link]
Steve is a project being developed by a group of museums that want the public to engage with their collections by allowing them to search for an item though a social filter. The way museum curator catalogues a collection is rarely the same as member of the public would search for it.
Curators rarely answer the question “What is this a picture of?”[link]
For example:

A curator may catalogue this image as Italy,futurism, painting, 1912, Balla. Giacomo
Whereas a person searching for it my use terms like dog, daschund, motion, blur
Steve is an attempt to democratize a collections catalogue, not by replacing the curators perspective, but by adding an additional layer of information provided by the public.
Bonus - Steve appears to be under a creative commons/share and share alike licence.
dude! great example anthony. we should find out what usability studies they did. 8o
Comment by draggin — January 17, 2006 @ 12:43 pm