Picasa -

For my niece's birthday, I made her a personalized coloring book out of photos from our family vacation. Pretty neat!

I did not edit the photos in Picasa to turn them into line drawings - just sharing them through Picasa.  Very easy to use, especially if you already have a Google account.  Picasa organizes your photos and images for you - sometimes this can be a little frustrating as it doesn't always use the same folder organization as your harddrive - but to share these, I simply clicked "Blog This" and it sent the images directly to a new post on my blog.  (By the way, I used Paint.NET to change the photos to line drawings.)