How can I get this effects?

by icons_are_hot
is it a brush or something like that or she just draw the lines with a default brush?

by pinxess
a time ago I remember that I saw a post about where to find this brush that is kind of a stain of a glass, but I couldn't find it.
where can i find it for download?

I'm using photoshop 9
thanks in advance! :)