Just found an AMAZING feat in Fiendish Codex 2: Divine Defiance. If you have Dispel Magic memorized (or the spell being cast), you can spend a Turn/Rebuke attempt as an immediate action to counter any spell or spell like ability being cast. You have to make a Spellcraft check to identify the spell successfully when you do this.
Is it just me, or is this a genuine caster killer feat? Combo it with Tenebrous as a Binder and now you can shut down casters rather decisively (since generally taking out their first spell really screws them).
This makes the old Binder 1/Archivist 3/Anima Mage 10/Tenebrous Apostate 5/Tainted Sorcerer 1 build that much more crazy. The Cleric version ain't half bad either.
JaronK