I was nosing around over at Quilt Channel and Planet Patchwork after Christopher from Quilt Channel commented just below, and I found a review for a fabric calculator. Now, if this is something you think is a great idea, I don't mean to make you feel bad. I think the fact that this is something I would never use says more about me than about anybody else! I know that a lot of people seem to figure the yardage for their quilts very exactly - but to figure the yardage you have to know exactly what you're going to do, and I rarely seem to know that going in. It's (partly) why I make scrap quilts - if I run out of fabric, I just use something else. But it's also because I don't think I would ever finish a quilt if I tried to do it that way; if I knew exactly what fabrics I was going to use, and exactly what the border was going to look like, I would just get bored and quit. If no two blocks are ever completely alike and you really have only a vague idea what your quilt is going to look like, it's a lot harder to get bored.
I guess you could call it the ADD approach to quilting.