The good folks at Shalimar Yarns are planning to do a knit-along for Arctium, in early November. Sign up for their newsletter and they'll be sending out more details and a special coupon, good through the end of the year, for a dollar off the pattern price. Sign up for the newsletter in the footer of their website.
You can see some of their other in-progress KALs and get to know the folks behind the yarn, over in their Ravelry group. I'll be there, answering questions, and encouraging everyone along. I would love to see you all there.
If you are interested in buying some of their yarn for the project (or any other project), a full list of their retailers are here including web retailers, at the bottom.