what is this and why is it climbing my glass?

[fLshgear]

here is a pic. i just setup the tank i have sand and some live rock. this is my first saltwater tank.

it is small, about 2-3 mm

http://i410.photobucket.com/albums/pp181/flshgear/IMG_9871Large.jpg

[muck]

asterina starfish

[Norstar]

+1

[fLshgear]

are they a good thing or more of a pest?

[pelle31]

They are good. I have tons of them.