Sharepoint calculated column Common formulas list http://office.microsoft.com/en-us/sharepointtechnology/HA011609471033.aspx
You've tried [Today] and [Me] here are some more functions http://office.microsoft.com/en-us/sharepointtechnology/CH100650061033.aspx
Introduction to the subject http://office.microsoft.com/en-us/sharepointtechnology/HA101215881033.aspx
http://www.sharepointblogs.com/mkruger/archive/2007/06/26/howto-using-sharepoint-calculated-columns-to-display-a-list-item-as-quot-x-quot-days-old.aspx
