EDIT: This stored procedure has been updated.

Here's a stored procedure that will check the integrity of each of the databases.  I've got it scheduled to run every night on each of our servers.  I recommend putting it into an Admin database (hey just name it Admin!) rather than in master.

CREATE    PROC isp_DBCC_CHECKDB
AS

SET NOCOUNT ON

DECLARE @dbid INT
DECLARE @DBName SYSNAME
DECLARE @SQL NVARCHAR(4000)

SET @dbid = 0

WHILE @dbid < (SELECT MAX(dbid) FROM master.dbo.sysdatabases)
BEGIN

 SELECT TOP 1 @dbid = dbid, @DBName = name
 FROM master.dbo.sysdatabases
 WHERE dbid > @dbid
 ORDER BY dbid

 SET @SQL = 'DBCC CHECKDB(' + @DBName + ')'

 EXEC sp_executesql @statement = @SQL

END

RETURN 0

GO