Sand Camouflage( Sandstorm, p. 51)
You can hide yourself in sand with a moment's notice.
As a standard action, you can quickly camoufl age yourself in any area of ash, dust, loose earth, or sand that is at least 1 inch deep. In areas with 1 to 11 inches of appropriate loose soil, you gain a +4 bonus on Hide checks. In areas with 12 inches or more of appropriate loose soil, you instead gain a +10 bonus on Hide checks. You must still have cover or concealment to make a Hide check, as described on page 76 of the Player's Handbook