I'm beginning to edit all my metadata now directly in my photo file EXIF info. I hate the fact that the tags that I've spent hours and hours inputting into Flickr are locked into their closed system. And to be fair at present your tags are just as locked into Zooomr's closed system as well, but at least with Zooomr I uniquely know that we are committed to figuring out a way to eventually get these tags back to our users and feel like I have more control to ensure that this happens working for the company. I'm sure that Flickr is just as committed in assisting their users in getting their tags out of Flickr but I don't have access to the internal workings of Flickr so all I can say is that I hate that I can't get them out today.
Anyways, the best solution to all of this for me at least, is to begin entering my meta data not into a photo sharing site but into the actual file itself. This way when I do upload it to Flickr or Zooomr or wherever, the metadata should carry over and the tags placed automatically.
Seems to me that the "you own your own data" principle should apply to your own metadata as well. Thomas has one way of asserting that (by embedding it in the photo's own datafile); but we need a more comprehensive and well-understood approach, within whole categories.
Seems to me photography is a good place to start.
Already sites like Flickr, Tabblo and Zooomer are leading the way by being open to users moving photos and data from one to the other in effect recognizing that the photo industry should no longer be "your choice of silo", but rather an open marketplace where relationships with customers provide the primary glue that holds the marketplace together.