Zooniverse attempts to describe astronomical and scientific objects.
Plus lots of other things you can do like identify animals out in the wild and tag and annotate World War I diaries,
What's the Score the Bodleian Libraries music collection of over four thousand digitised scores, mostly piano music from the nineteenth century, many of which have illustrated covers, are now available online for metadata creation.
Remember Me? the United States Holocaust Memorial Museum provides photographs of young survivors for volunteers to help identify.
Linked Jazz creates links between jazz information discovered within oral histories
What’s on the menu? NYPL’s project to restore old menus.
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US National Archives. Citizen Archivist. Transcribe, Tag, edit historical documents.
Then University of Iowa Libraries is using crowdsourcing for its Civill War transcription project and a handwritten cookbook collection.
Last year the Chicago History Museum used crowdsourcing as a tool to gather ideas for a new exhibit.
Chicago's Newberry Library - transcribing letters from IL Civil War soldiers.
I-Share asks for user tags and reviews. (Is it switched on?)
ILState University - transcribing a WWI seaman's diary
Tagging photos
Art in BQR - Viewers' Comments
Feedback on students' impressions of services
Students asking and answering FAQs