You can cast spells using metamagic feats more easily than normal.
Prerequisites: Four metamagic feats, Spellcraft 30 ranks.
Benefit: The spell slot you must use to cast a metamagic spell is one level lower than normal (to a minimum of one level higher than normal). For instance, you could cast a quickened spell as a spell of three levels higher than normal rather than four levels higher.
This feat has no effect on a metamagic feat that requires a spell slot one level higher than normal or does not require a higher-level slot.
Special: You can gain this feat multiple times. The effects stack, though you can’t lower the level of any metamagic spell’s slot to less than one level higher than normal.
Source: Dungeon Master’s Guide (version 3.5), page 210.