Homasote. This is technically a compressed fiberboard product that is sometimes used for soundproofing and insulation. Great for large bulletin boards because it takes pins really easily, you can cover it with fabric, paint it, or frame it. It's about $12 for a 4 foot x 8 foot sheet. - Cheaper than cork sheets at Hobby Lobby.
Wine Cork Bulletin Board: Perfect for any wine lover, this unique bulletin board has been handcrafted from an authentic Napa Valley wine barrel and includes the metal barrel band. Approximately 23" in diameter and filled with a variety of wine corks, it's a show-stopper.