Rock Catcher,
If you getstuck without a good factory bobber stop, regular sized rubber bands work great also...I've had to use them many times! They won't hold quite a strong or long as what kid Sauk mentioned (especially if using extra weight above the jig), but in a pinch are great. Just run the band around the line and back through itself, tie an overhand to lock down the hitch you've created and trim the excess. I also make my own stops when I'm feeling productive by cutting up a cocktail straw into inch and a half pieces and tying a nail knot around them using floss or dacron (sounds like you flyfish and might have leftover backing around...works fine).