Working on the design of platform for keeping annotations, I came up with a new way of tagging items, which I call 'Drag to tag':
Drag the tag to the words that are typical for the webpage to add tags (for its bookmark). No typing required!
The tags that are shown in the text could be made resizeable to create tags longer than a single word. A similar pattern would be selecting a word and clicking/tapping the tag button, which would be especially handy for tags longer than a single word.
Though it looks so simple, I haven’t seen Drag To Tag in any application yet. Do you know an application in which this has been used?