Bil Kleb wrote:
...
> She says that she can't figure out how to /append/
> to a CSV file using Ruby's standard library.
...

Not sure if you read ruby-forum (http://www.ruby-forum.com/)
but a response ther indicates that you can do this via the CSV::Writer:

File.open('csvout.csv', 'a'){ |outfile|
  CSV::Writer.generate(outfile) do |csv|
    csv << ['c1', nil, '', '"', "\r\n", 'c2']
  end
  }


Cheers
Chris