To straighten yarn that has been previously knit/crocheted. A kettle with hot water to just below the spout. Pass the yarn through the lid, and up through the spout, slowly pulling it through so the steam unkinks the yarn.
Build your own art yarn spinning wheel from PVC pipe and craft store supplies. Instructions and supply list are included in my book that will be published November 1st, 2013. You can purchase the book here: http://www.shopneauveau.com/product/spinning-and-dyeing-yarn-the-home-spinners-guide-to-creating-traditional-and-art-yarns-hardcover