Have you heard of Cagora? These guys have really built a unique application. This site has over 20k communities, all by geography and special interest. They also share revenue with their users… Very interesting concept. The site also has some very "ajaxy" functionality… I had the opportunity to meet the creator, Rob, and he's an Australian Entrepreneur with some serious drive. Take a look… One very unique thing about this site is that you can find anything anywhere… thing "browse," not "search."
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Feedly is superb. I have been using it for a few months now and love it. It is technically a a ff extension, but still a great way to start your browsing.
I really like Netvibes and iGoogle.