For all you Tube Quilters out there, Cozy Quilt Shop has a chart on its website that tells you how wide to make your tube in order to have a finished block of a certain size. They use it in connection with their Strip Tube Ruler and refer to using it for Half Square Triangles. However, you could just piece your tube to the the width that they give. Thought it might be helpful.
http://www.rndv.com/PDFs/STRBonusGuide.pdf
Additionally, if you sign up for their newsletter, you receive a free pattern for a tube quilt.
http://www.cozyquilt.com/aspx/EmailNewsletter.aspx
And, no, I don't have any affiliation with Cozy Quilt Shop except that I give them my credit card number on occassion when I am ordering something from them.