This is a simple bit, but useful.
C:\data\ruby\PoliticalBits]ruby -e 'puts $:'
C:/data/support/ruby-186-26/lib/ruby/site_ruby/1.8
C:/data/support/ruby-186-26/lib/ruby/site_ruby/1.8/i386-msvcrt
C:/data/support/ruby-186-26/lib/ruby/site_ruby
C:/data/support/ruby-186-26/lib/ruby/1.8
C:/data/support/ruby-186-26/lib/ruby/1.8/i386-mswin32