This cute trivet is featured in the Spring 2010 issue of Stitch and is designed by Kevin Kosbab. You can find him online here. Mr. Kosbab is a very talented man; I think his designs have been featured in every issue of Stitch!
I worked up his 'plaid curves table runner' a few weeks ago and love the results.
My trivet is worked in wool rather than wool felt (I didn't have any wool felt on hand, but have a large supply of wool blazers and coats). Since I used a plaid wool instead of wool felt for the main body, it left a slightly raveled edge that I didn't like, so I encased it with some linen bias binding.