So far I'm liking Sparkbox. There's an "uncategorized" category where new stuff winds up, and as soon as I tag it it's pulled out of that (so no digging through reams of images to find the few that don't have any tags and are therefore unfindable). I've only pulled my vintage sewing patterns in so far, and I've got some 20 tags set up for them (year, part of clothing, publishing company, in-stash, to-sew), but it's working pretty well. Tags can be grouped but never duplicated, so I'm still thinking about how I want to organize everything before I really dig in to the big project - my historical reference stuff. It's easy to rename tags, though, so it's not the end of the world to change my mind later.