Target has begun selling bamboo sheets and towels. They are reasonably priced at $40 for a sheet set, and $20 for two towels. Unfortunately, the bamboo content is not all that high — 60% for the sheets and 40% for the towels, and the rest of the fabric is conventional cotton (which requires large amounts of pesticides to grow). Organic cotton or hemp fiber would have been more efficient.
See more information in this article from the Green Guide.