Google GeoLocation error with rails application?

Question

I am trying to get google-geo to work, but I am seeing errors.

#!/usr/bin/ruby

require 'Google-geo'

mykey = 'blahblahblah'
addy1 = 'xxxxxxxxxxxxx' # xx, yy

geo = Google::Geo.new mykey
res = geo.locate addy1
puts res.coordinates

...and the error:

/Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:55:in require': cannot load such file -- Google-geo (LoadError) from /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:55:inrequire'
from pdev.rb:6:in `'

Not sure why it can't load it as it's just installed. I can't get anything to work in irb either.