So in many of the Search posts I have written I refer to a whitepaper by IDC called 'The Hidden Costs of Information Work', we cannot give this to you for free unfortunately for IDC licensing reasons - but for those who do wish to review it, IDC make it available here:

http://www.idc.com/getdoc.jsp?containerId=201334

There is some good commentary from Kevin Johnson the Co-President, Microsoft Platforms & Services Division (not to mention a cheesey photo :-)) here:

http://www.microsoft.com/presspass/features/2006/may06/05-17EnterpriseSearch.mspx

Enjoy!