There is a new kind of feat called the 'Eldritch Feat'. They usually require a very high stat, but they affect spells without raising heir level the way Metamagic feats do.
The feat that I remember offhand (been awhile since I looked through it) is 'Lace Spell' which lets you alter the damage type a spell does. For example, you could lace your Fireball with positive energy.
There's a wide variety of spells, but again the ones that stand out in my memory are the 'Mark' spells. These spells have a certain effect on the recipient that lasts until the duration expires, *or* the recipient can choose to expend the spell's force all at once for a different effect. I think 'Mark of Fire' protects you from fire damage, and if you end it prematurely you can make a fire attack.
There's also some nifty magic items, like the Rods of Branding (usable 1/day, they put a magical brand on the subject with some effect - like the inability to use one's magic) and the Ring of Blue Conjures (surrounds summoned creatures with a blue aura that gives them combat bonuses)
J