If you need to find, if so and so object (stored procedure, table, function) exists in the database, following queries could be of help to you :
SELECT * FROM SYSOBJECTS WHERE NAME LIKE '%ObjectName%'
If you know the type of object, even better :
SELECT * FROM SYSOBJECTS WHERE XTYPE = 'U' AND NAME LIKE '%ObjectName%'
-- 'U' denotes a User Table
If you need to find out if the object exists in any of the databases on the system :
EXEC sp_MSforeachdb 'SELECT * FROM ?..SYSOBJECTS WHERE XTYPE= ''U'' AND NAME LIKE '%ObjectName%'