Where/how do you tag an attachment?
JoAnne -

It seems to me that the most likely scenario for adding/tagging attachments is in the creation of activities - I tested adding a tag for attachments in the demo site, and when I created a meeting activity and opened up the attachment section, the tag field was there: http://screencast.com/t/fNc98uR6Uq  

What puzzles me, however, is that there is no apparent way to search for attachments or activities/contacts with attachments (which is different from searching within the attachments, which would be an entirely different ballgame), other than Search Builder (which is somewhat opaque for a lot of the Civi users with whom I work).  I see from this message that others have asked the same question - until the attachment tags are searchable, the usability is a bit limited IMHO.

Hope this helps,
Lesley