Cats lick iPhone sync cable

I have several USB cables hanging near my desk from a hub. Both of my cats will consistently lick the white iPhone sync cable, and ignore the others. I know this is not the most pressing issue iPhone users face, but it's so bizarre that I was wondering if anyone else had experienced it with their cats. It's too bad it's not the ethernet cable, because I could understand their licking CAT5. Sorry for the pun, but this is an actual question I'm asking.

Thanks.

Dan