Eigenclass
   Repository of Ruby code, information, culture: writings, development resources, unusual idioms, hacks that bend the language, reviews and improvements of 3rd-party code, news on development: changelog summaries, translations of Japanese communications.
   http://eigenclass.org/

Entrepreneurship: Life Long Learning
   Covers many topics, many involve Ruby, Rails, related topics. Kevin Tew.
   http://blog.tewk.com/

Nick Sieger
   Covers many aspects of Ruby, Rails, related topics.
   http://blog.nicksieger.com/

O'Reilly Ruby
   Covers many aspects of Ruby, Rails, related topics. O’Reilly Media.
   http://www.oreillynet.com/ruby/

On Ruby
   Covers many aspects of Ruby; by Pat Eyler.
   http://on-ruby.blogspot.com/

One, Step, Back
   Covers many aspects of Ruby: Ruse, Rake, Rails, RubyGems, RailsConf (US, Europe).
   http://onestepback.org/

PJ Hyett
   Musings on life, Ruby and Rails programming, and everything in between; by part owner of Err the Blog, Err Free.
   http://www.pjhyett.com/

PuneRuby: Everything on Ruby/Rails
   Covers Ruby and Rails, by the largest Ruby User Group (RUG) in the world, based in Pune India.
   http://www.puneruby.com/blog/

Ruby
   Covers a few aspects of Ruby: Rails; by Martin Fowler. MF Bliki.
   http://martinfowler.com/bliki/ruby.html

Ruby Inside
   Covers many aspects: daily tips, news, code, fun.
   http://www.rubyinside.com/