The YAML Specification is independent of the YAML perl package.

I use YAML for all my human-readable configuration files and have even used YAML for this specific purpose. Here's a sample test from the test suite (actions map directly to Test::WWW::Mechanize methods):

- url: BLAH.cgi
  title_is: My Spiffy Page
  actions:
    - submit_form_ok:
        form_name: magic_form
        fields:
          mstat: M
          mtype: 99
    - contains:
        - Mbr First
        - Mbr Last
    - lacks:
        - Amt Due
    - submit_form_ok:
        form_name: magic_form
        fields:
          # delcd will still be 'A'
          mstat: ""
          amdue: 50
          chk_amdue: checked
    - contains:
        - Mbr First
        - Mbr Last
        - Amt Due
[download]

Update: My employer (National Financial Management) has granted me permission to modify and release the test driver for these files on CPAN. Watch for Test::WWW::Mechanize::YAML on CPAN!

Update 2: Released Test::WWW::Mechanize::Driver on CPAN!