There is some stuff called earthquake putty. You can find it where they sell the felt pads or things for hanging pictures. Even the stuff that people use to put up posters without tape. It's just a putty you knead and the put a blob under the item you don't want to move around.

I would get the white painters tape if your woodwork is white and basically tape the cords along the window ledge. Dark tape if the woodwork is dark. That way you can peel it off easier. I know someone was mentioning something which peels easier than the blue tape, but I don't remember. I've had really good luck with the white tape pulling of easily after several weeks.

Gloria