I hate to reply to my own post, but this is the solution I've come up with:

require 'cgi'

class CGI
  module QueryExtension
    def [](*args)
      if @params[*args]
        return @params[*args][0]
      end
    end
  end
end

I saved this in /usr/local/lib/site_ruby/1.6 as scgi.rb. Now I can use the
CGI class as follows:

travis@aop:~$ irb --simple-prompt
>> require 'scgi'
=> true
>> q = CGI.new
(offline mode: enter name=value pairs on standard input)
name=travis
like=ruby
like=linux
=> #<CGI:0x4027e034 @params={"name"=>["travis"], "like"=>["ruby", "linux"]} ...>
>> q["name"]
=> "travis"
>> q.params["like"]
=> ["ruby", "linux"]
>> q["like"]
=> "ruby"

I was wondering where I could post such a modification so that others could
use it as well. It seems a bit silly to post a 10 line hack to the RAA.
Is there a page on the Wiki that would be appropriate?

Thanks,
Travis