Imitate hand-drawing line

Does anybody know how to imitate a line drawn by hand, i.e., the line shouldn’t be straight, but “wavy”. Also it would be nice to animate the process of drawing of such lines.

Are you developing a like game? This blog would be helpful to you http://blog.sina.com.cn/s/blog_61d2d3f501011vgz.html I’m sorry it’s written in Chinese (by a developer), you can read it via google translation.