Get some split loom tubing from your local car stereo shop, etc. This will make the speaker wires look big and provide some limited protection and won't cost much at all.
Here is one web site that has prices and a picture:
http://www.allelectronics.com/matrix/Split_Loom_Tubing.html
Here is one web site that has prices and a picture:
http://www.allelectronics.com/matrix/Split_Loom_Tubing.html