mushroom pillow (sold out!) UO SKU #20942397. Update 8/15/12: Actually, just found out that this product was copied directly from Paragon Needlecraft Creative Stitchery "Mushroom Forest" Pillow Kit # 0433. Urban Outfitters, original as always.
Download the mushroom pattern and enlarge to desired size on a printer. (For extra-large results, you may have to visit a local copy center.) Use the patterns as templates to cut shapes from fun, lively fabric. Iron the fabric onto fusible webbing (available at crafts stores), then adhere to the wall. Designer Matthew Mead used Mod Podge to make his mushrooms stick.