For $4 or so, you can get enough parts to make more bobbers than I'll use in a lifetime, The only trick is getting clips with a big enough hole that they don't freeze up. You can cut these to size, similar to the "Icebusters" on the market for over $1 each:
Checkout the collection of inventions at
http://www.iceshanty.com/ice_fishing/index.php?topic=15334.0. If you have any related ideas, post a note there!
Have fun,
Paul