Macintosh:bin paulrl$ sudo gem install ruby-openid
Successfully installed ruby-openid-2.1.6
1 gem installed
Installing ri documentation for ruby-openid-2.1.6...
Installing RDoc documentation for ruby-openid-2.1.6...
Macintosh:bin paulrl$ irb
irb(main):001:0> require 'ruby-openid'
LoadError: no such file to load -- ruby-openid
	from (irb):1:in `require'
	from (irb):1
	from /usr/local/bin/irb:12:in `<main>'
irb(main):002:0> gem 'ruby-openid'
=> false
irb(main):003:0>