For my first attempt, I used a paintbrush in Photoshop and got fairly good results. The thickness of the line depends on the angle of the pen. I don't really like the way the line almost disappeared in some places. Because Photoshop is a pixel based program, it's not the ideal way to draw, but in a pinch, it works just fine.
My next drawing was created in Illustrator using a pencil tool. The pencil makes for a more precise drawing, but it looses the whimsical sketch feeling. The good thing about a vector based drawing program is that I can enlarge or shrink the drawing to any size I want, and not lose any quality at all. If you are interested in designing quilt patterns or creating fabric designs, this is the program to use (IMHO).
I can see myself playing with this a lot more in the future. There are so many possibilities.
If you use a tablet, I would love to hear what you are doing with it. Drop me a note.