Transdimensional spellSpell is a feat that was originally in Tome and BloodUnapproachable East (p. 45) and now is in Complete Arcane, I believeComplete Arcane (p. 84) and Complete Divine (p. 85). It allows one to cast spells that affect incorporeal creatures as though they were corporeal.
There are also spells and effects from GhostwalkGhostwalk that can drag incorporeal creatures into manifested corporeal bodies.