Thanks for asking this question!! I have been wondering the same thing. I usually use excel. I have found that I can copy a "picture" of my fabric(s) from Fabric.com (or some other internet site) and change the size to fit the blocks I am considering using ... then I can make as many copies as I want and play around with the arrangements while I watch TV. This isn't perfect as I can't figure out how to do triangles... but now based on the other responses there are some other software out there that I can check out.
