file.rb

require "rubygems"
require "celerity"

c = Celerity::Browser.new :log_level => :off
c.goto "google.com"
p :url => c.url

page = c.page

c.goto "yahoo.com"
p :url => c.url

c.page = page
p :url => c.url

c.text_field(:name, "q").value = "celerity"
c.button(:name, "btnG").click

p :url => c.url

# # output:
# 
# {:url=>"http://www.google.no/"}
# {:url=>"http://www.yahoo.com/"}
# {:url=>"http://www.google.no/"}
# {:url=>"http://www.google.no/search?hl=no&q=celerity&btnG=Google-s%C3%B8k&meta=&aq=null&oq="}