JON UDELL recalls the conventional wisdom around tagging items in your digital stash. "People could never be bothered to invest effort in tagging their stuff. What del.icio.us and then Flickr and then a host of other web applications showed is that people will invest that effort if the activation threshold is low and the reward is immediate." That's what works for me. I like seeing tags converge on travel destinations, professional events, and family albums. If you tag it with a shared term, others can find stuff without knowing where the stuff is located. Data from the opt-in software quality metrics (SQM) feature — which relays anonymized usage data to product teams for analysis — says a lot of people voluntarily tag their stuff. People are using tags to keep big collections--like photos or music--better organised.
In my personal storage locations offline, tagging things mean they have additional value when shifted up to the web.
Udell has a screencast where he distinguishes between foldering and tagging. He says, "In principle you don’t need a folder hierarchy rooted in the file system, and doing away with it entirely would reduce the concept count. In practice that’s not yet possible, if only because cameras don’t produce endless streams of uniquely-identified files. When DSCF0004.JPG rolls around again, you have to put it into a different file-system folder than the last time."
I use tags in an Adobe Photo Library and the program remembers my tags--that's helpful. But it looks like Windows Vista does all the most common photo file management tasks without the need to purchase additional software.