If you want to see some tough questions to ask vendors who are claiming "ITIL compliance", see ITSMWatch
http://www.itsmwatch.com/itil/article.php/3644451It then branched out into a discussion of what verification means:
http://www.itsmwatch.com/itil/article.php/3646441and then
http://www.itskeptic.org/node/72It is an amusing little debate