1. The Kayak dev key is here:

  http://www.kayak.com/labs/api/search/developerkey.html

2. Using your email as a perl string requires a \ in front of @

3. I had to install many packages before the Perl script ran on a basic EC2 Linux instance:

  sudo yum install gcc perl-CPAN perl-libwww-perl expat-devel gnuplot

4. Before installing the CPAN packages he mentions:

  sudo perl -MCPAN -e 'install Digest::SHA'
  sudo perl -MCPAN -e 'install Test::More'
  sudo perl -MCPAN -e 'install XML::Parser'

You may have to do additional debugging and install other CPAN packages.

5. Install the CPAN packages he mentions

6.

  nohup perl SerenDaemon.pl > errors.txt 2> exceptions.txt < /dev/null &