The list is divided into a few different areas, each representing stages of the process of innovation: Opportunity Identification, Brainstorming, Research, Prototyping, Validation and Implementation.
Some of these tools and sites are well-known (e.g., Amazon, eBay, LinkedIn, Pew Research) and some are new, at least to me. Some notable mentions (with descriptions courtesy of BrainReaction) on this list include:
SpyFu.com: Competitive intelligence for your keywords that tells you approximately how much money your competitors are spending on pay-per-click ads and what terms they are using for advertisement.
Emily Chang’s Ehub: Emily does a great job of cataloging the latest Web 2.0 applications in her Ehub database. Many of these applications have become instant hits with the online audience and one can detect amazing opportunities by looking at the adoption rates of applications like Twitter.
eMachineShop.com: Website that provides you a free CAD tool to design your product and to upload your design to them so they can actually manufacture it and ship it to you. You can order just one piece or a thousand, and the pricing varies according to materials used. The beauty of this software is that it gives you instant quotes when you are designing the prototype, so you can adjust it to make it cheaper.