I blogged in the past on the subject of Salesforce.com IDs: click here to see it.
The wonderful thing is that SFDC were listening! Not just to me, but I was a voice in the crowd. They responded in the Spring ’12 release with a new function to be used in formula fields:
Syntax example: CASESAFEID(Id)
Official documentation link: http://login.salesforce.com/help/doc/en/customize_functions_a_h.htm#CASESAFEID
It’s that simple. Just set up a new custom field with this as the formula and use it in your reports.
[Note: SFDC = SalesForceDotCom]