I had been looking for an app that would merely tag messages in Mail to compensate for poorly expressed subject headers. Mailtags does the job well, but does too many things. Then along comes Tags with its clean and fast interface for tagging virtually anything, including Mail messages. Glad I waited for it - am well into the evaluation period and very likely to pay the reasonable shareware fee after another week of looking for bugs (none so far). Tags makes creating and assigning (and removing) keywords easy and fast. I think of it as a cross-indexing complement to Spotlight and ABC Launch, especially for databases and spreadsheets that Spotlight cannot reach into. I do not tag a lot of things, but for certain projects the app makes a very good consolidator of different types of files, folders, URLs and email messages. The only thing I could wish for now is an ability to tag individual records within databases and spreadsheets.