Search all columns in list of tables for particular string
You can query syscolumns and sysobjects in each database to get the information you need.

select 
  distinct so.name as TABLE_NAME,
  sc.name as COLUMN_NAME
from 
  syscolumns sc,
  sysobjects so
where 
  sc.id = so.id
and   sc.name like '%searchstring%'
order by so.name


If you need to limit your search to specific tables, then you can add an additional 'and' clause:

and so.name in ("Table1","Table2","Table3")