Quicken Spell (Feat)
You can cast spells in a fraction of the normal time.
Prerequisites: Caster Level 9
Benefit: You may use this feat once per round to cast a spell as a swift action. You can perform another action, even casting another spell, in the same round as you cast a quickened spell. A spell whose casting time is more than 1 round or 1 full-round action cannot be quickened. Weirdly enough, you can even use this feat on a spell that is cast as an Immediate action, and it actually slows it down to a swift action.
NOTE: Casting a quickened spell doesn't provoke an attack of opportunity.
You can apply the effects of this feat to a spell cast spontaneously, so long as it has a casting time that is not more than 1 full-round action.
Level Increase: +4 (A quickened spell uses up a spell slot four levels higher than the spell's actual level.)