You spray sand with your acrobatic maneuvers.
Prerequisites: Wis 13, Tumble 8 ranks, Sand Dancer.
Benefit: In any round when you first move at least 10 feet using your Tumble skill in an area covered in a layer of at least 1 inch of ash, dust, loose earth, or sand, you can take a standard action to hurl a spray of sand into the eyes of all creatures in a 5-foot-radius burst. Those within the area must make Fortitude saving throws (DC 10 + ½ your character level + your Wis modifier) or be blinded for 1 round.
See Determining Loose Soil for finding the chance of sufficient ash, dust, grit, loose earth, or sand existing to use this feat.
Source: Sandstorm, page 52.