Here's one I built a few years ago, I drilled small holes around the bottles and used floral wire to put it to put it together. I tie the string to the bottle handle and unscrew the bottle cap when I want to get the minnows out.
http://i14.photobucket.com/albums/a3...9/100_2020.jpg
http://i14.photobucket.com/albums/a3...9/100_2022.jpg

