You can use your breath weapon one more time per day than you normally could.
Prerequisites: Breath weapon with limited uses per day, Extend Spell or Extend Spell-Like Ability.
Benefit: You can breathe one additional time per day. The interval you must wait between breaths is 1 hour.
Special: You can gain this feat multiple times. Each time you take it, you can breathe one additional time per day.
Source: Savage Species, page 31.