I was recently needing to search an entire database for a particular string. I needed a script that would do this, so I went searching. I found a really useful script here: http://vyaskn.tripod.com/search_all_columns_in_all_tables.htm. I am reposting the code here for my own future reference, and to share the script with you. But all the credit goes to the original creator.
Here is the code you need to execute against the database. It will create a stored procedure in the database that can then be used to perform the search.