Saw this deal today on JensonUSA. Intense Spike tires (26x2.25" 2-ply folding bead) for $13.99 each. Cheap way to get some mud spikes for your bicycle before Nationals in case it decides to rain...which of course never happens at Beech Mt. ).
http://www.jensonusa.com/Intense-Tire-Systems-Spike-Tire
http://www.jensonusa.com/Intense-Tire-Systems-Spike-Tire