In a game I play in my cleric uses Divine Persistant spell (He is a priest of Vecna with Planning and Magic Domains as planning in the Complete Warrior has Vecna as a listed God with access to the domain) again I apply the nuke theory if I abuse them the DM will hammer me with something to make an encounter fair. I also use divine fortify spell which actually makes great sense as a divine metamagic feat (although a bit weak from a powergaming standpoint). Again the feats are balanced as listed by Customer Service and for the additional reason that the DM should be creative enough to bypass any parlor trick a spellcaster comes up with.