The British Library is home to over 150 million published items; a copy of every publication—whether a book, newspaper, magazine or periodical—made each year in the UK and Ireland is archived there. In partnership with Microsoft the BL digitised tens of thousands of out-of-copyright publications from the 17th, 18th, and 19th centuries. As part of this process they acquired millions of images from these pages and they've now released them into the public domain on the Flickr Commons. The collection includes illustrations, satirical comics, geological diagrams, maps, illuminated letters, and maybe a few photos. Now that they have been released into the public domain they are free for anyone to use, remix, and repurpose as they wish. But the BL is also asking for help to find innovative ways to allow people to navigate and search these images; while the library knows the book, volume, and page from which each image was drawn, it knows nothing about them indivdually. It wants to crowdsource descriptions of what each image portrays to make the collection a lot more useful, as well as develop an efficient tagging and metadata system.
You can take a look at the images over on the British Library's Flickr stream and if you have any bright ideas to help them with the project, they'd be interested to hear from you, too.
(Headsup to Ars Technica)