Need an ID

[Zen685]

I have these little critters on my glass. I think I've seen them identified before but I can't find it. Can anyone identify this and wheather it's good or bad? BTW it's magnified 10x.

http://flickr.com/photos/7145699@N06/432785702/

[Redhawk44]

looks like flatworms, are they a rusty tint?

[fishome25]

looks like the white flatworm, not bad to have