Flickr has more than 4bn photographs. An option in Advanced Search allows you to limit your search to Creative Commons licence images only, which can be used for various purposes, within the limits of the licence.
Tag Galaxy works on the principle of a 'galaxy' of images which create different 'planets' of images. Visually appealing and great fun to use.
Behold searches more than 1,000,000 high quality images from Flickr within the Creative Commons collection. It uses both aesthetic and technical quality indicators so so you don't have to sift through hundreds of photos to find a good one.
Panoramio is a geographical image search engine. Choose your place (e.g. London, Oxford Street, new York) and Panoramio will display images from that location, superimposed on a Google map.
Seeklogo database has more than 200,000 images available for viewing and downloading. Straightforward and easy to use if you need a logo.
CoverBrowser searches through the covers of comics, books, DVDs, games, music and movie posters to find images. With over 455,000 illustrations, you can search by keyword, title, colour or artist. This is a sister site to VintageAd.
VintageAd contains over 123,000 advertisements, arranged chronologically - with some going back to the early 1800s.
Phil Bradley in CILIP Update, July 2011