You could also use a orange spot gobie. They do a good job at sifting the surface of the sand.
http://www.liveaquaria.com/product/p...pcatid=220&N=0
Nassarius snails do a great job as well.
http://www.liveaquaria.com/product/p...catid=1133&N=0
You can also get a tigertail sea cucumber
http://www.liveaquaria.com/product/p...pcatid=712&N=0
There are a few different fish that do the same job but I would not suggest them. The yellow headed sleeper goby. It sifts the sand threw its gills while swimming up in the water collum and spreading it all over your corals and clams.
And the two spot or signal goby will usually not last a long time. They tend to starve in the aquarium.
Chris