I've seen on blogs where they have uploaded pictures of quilts and free hand drawn quilting motifs on the quilt. What is the name of that program that allows them to do that?

Any paint program should let you mark up a photo. You can use the paint program that comes with your machine. Look under "All Programs" / "accessories" / "Paint"
Load the photo of your quilt to your pc, open the paint program then open the photo. Use the pencil tool. It's rudimentary , but it will work.

nope this program allows your to draw with a pin on the screen

Not sure what you are asking. If you want to draw with a pen instead of the mouse, you can get a digitizing tablet to replace the mouse, for instance a Wacom Bamboo:
http://www.cdw.com/shop/products/Wac...s/1863474.aspx
This will work with most graphics applications, like paint, but check for compatability with the manufacturer

If you want to draw directly on the screen with your finger or a stylus you need to get a tablet computer, like an IPAD.

I think your best bet would be to contact the author of the blog where you saw this and ask them what they use.