Online Reputation/Recommendation systems

It is interesting to see how the Web is increasingly being used to help as a reputation/recommendation system.

Online recommendation

On the work front, there is a good chance that LinkedIn.com can give you some background about a person you are about to meet for the first time. For many, the ratings & recommendations for books on Amazon.com help in deciding on making a purchase. StackOverFlow.com is a unique forum for software developers that not just has answers but also ratings for those answers through "crowdsourcing".

I hope the infrastructure/frameworks for building such reputation/recommendation systems become more easily available & configurable so that developers can build more meaningful websites.

Dear Reader, what websites do you frequently look up for recommendations or validating information?

Related:
Preparing your online profile for employers
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