TagTeam use cases

Provide current awareness

Help people stay abreast of new developments in any field, or on any topic, with real-time alerts.
Take advantage of the fact that every TT tag (and remix feed, and search) publishes a feed in real time. If your project has one main tag, publicize it and invite people to subscribe to its feed. If your project has a series of important tags, publicize them all and let users choose the ones of interest to them.
Take advantage of the way TT hubs can crowd-source the job of finding new or important developments on any topic. Your current-awareness feeds can be more comprehensive than similar feeds built by individuals, even dedicated individuals.
The Open Access Tracking Project (OATP) uses TT this way.

Take advantage of the fact that TT stores tag records for powerful boolean searching.
Take advantage of TT's unique support for folksonomy in, ontology out. As project managers refine the standard vocabulary or ontology for the topics they want to cover, they can implement their decisions through tag filters.
The Open Access Tracking Project (OATP) uses TT this way.
Suppose that a blogger blogged and a tweeter tweeted all the items that a TT tagger tagged. The TT version would be much more useful later.
- Users could search the blog, twitter account, or TT hub by keyword. From that angle, they'd all be roughly on a par. But users could also search TT by tags, greatly reducing false positives. (Not all items mentioning food make it a major topic; not all items about food mention it all; searching for items tagged with food is a better way to get all and only the major items.) Blogs and Twitter feeds can use tags too, but they cannot systematically change tags, retroactively and prospectively, to reflect an evolving standard vocabulary or ontology. Nor can most of them search for boolean combinations of tags. Nor can most of them share a URL to the tag library for all only only those items with a given boolean combination of tags.

Individual researchers or large research projects can tag online items relevant to their topics. This helps them, of course. But it also helps others doing research on the same topics.
The Open Access Tracking Project (OATP) uses TT this way, and even has a page of recommendations on how to use the hub to facilitate research on its topic, open access. (Analogous recommendations would apply to research projects on other topics.)

If a project wants to catalog a large number of entities, and if the entities are taggable, then tagging them in TT can supplant or supplement traditional cataloging. And of course the resulting tags will support tag feeds, remix feeds, boolean searching, retroactive revision, and so on.
Items are only taggable if they have unique URLs. So this wouldn't work for print books, but it would work for online digital books or online metadata records. It wouldn't work for plant specimens, but it would work for online digital photographs of plant specimens. It wouldn't work for abstract ideas, but it would work for any online digital representation of those ideas, such as online digital dictionary or encyclopedia entries.
To catalog physical objects, combine TagTeam with a project to create taggable online records, simulacra, or photos of those objects.

If a project wants to maintain a continuously updated list of recommended readings, it can tag the readings and publish the recommendation feed on a web page.
- The Data & Society project uses TT this way.
Also see how the Open Access Tracking Project (OATP) describes a method for OATP participants to create feeds of their recommended readings. The same method could be adapted to any TagTeam hub.