A while back we were discussing fabric strip cutters here. I just got an email today from Nancy's Notions and she is selling one there now. It resembles a paper cutter and uses a 45mm blade and it is advertised as cutting up to 4 layers of fabric. A bit spendy at $39.98 but after the sale it will be $49.98.

http://www.nancysnotions.com/NNVia/viaImagePageTacony.jsp?searchText=DDSC&pd=Donna%20 Dewberry%20Strip%20Cutter