List all user tables and columns in a database.
List all columns in all tables in a SQL Server 2000 database.
FROM SYSOBJECTS SO INNER JOIN SYSCOLUMNS SC
ON SO.ID = SC.ID
WHERE SO.XTYPE = 'U'
ORDER BY SO.NAME, SC.NAME
List all columns in all tables in a SQL Server 2005 database.
FROM SYS.OBJECTS SO INNER JOIN SYS.COLUMNS SC
ON SO.OBJECT_ID = SC.OBJECT_ID
WHERE SO.TYPE = 'U'
ORDER BY SO.NAME, SC.NAME

Oh well...