Suggested raw materials for your mash up

This list of sources is not complete, and entrants are not required to use any of the resources listed here. Rather, the list is intended to provide a set of pointers and suggestions that entrants may find helpful.

Web Services, APIs, etc

Talis Library Platform APIs
A9 OpenSearch
Alexa Web Search Platform
Amazon Web Services
eBay Developers Program
Flickr Services
Google Web APIs
Google Maps API
MSN Search Developer Tools
OCLC's xISBN service
ThingISBN, from LibraryThing
Yahoo! Developer Network

Tools, communities and advice

Greasemonkey
Library of Congress' list of Search/Retrieve via URL (SRU) servers
ProgrammableWeb
Z39.50 Target Directory

Feel free to add further suggestions in the general competition forum, here.