I really like the Google+ interface. The use of circles and the excellent graphic layout really set it apart. Hangouts are another great feature. The linked article includes a great infographic as well.
If you’re on Google+, look me up 🙂 +Stuart Auld
http://www.jeffbullas.com/2012/10/05/64-google-marketing-and-branding-tips-infographic/
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