Exhaled Barrier( Races of the Dragon, p. 101)
You can use your breath weapon to create a wall of energy.
breath weapon, Dragonblood subtype,
When you use your breath weapon, you can choose to create a 10-foot-by-10-foot vertical plane of energy instead of producing its normal effect. The opaque wall's near endpoint begins at any corner of your space and extends in a straight line for 10 feet or until it contacts a solid surface. The wall lasts for 1d4 rounds. Any creature passing through the wall takes damage equal to that normally dealt by your breath weapon. If you create the wall so that it appears where creatures are, each creature takes damage as if passing through the wall. Either way, a successful Reflex save (DC 10 + 1/2 your HD + your Con modifier) halves this damage. If your breath weapon doesn't deal energy damage, the wall deals fire damage. If your breath weapon doesn't deal damage, the wall deals 2d6 points of fire damage.