Yay bubbles! I have a couple of really old 'unbelievable bubble things' in a closet somewhere that haven't come out to play in far too long. On a reasonably humid day, find a good updraft somewhere and you've got hours of soapy fun.
On a related note (and I am not sure if you deal with this in your book) over the last several years more and more dish soap has become 'ultra concentrated' or worse 'antibacterial', both things which seem to negatively affect bubble solution (not to mention that I don't want to be spreading antibacterial crap all over the place). Recently Palmolive has put out a 'pure and clear' version of their dish soap which has no color, no antibacterial crap and best of all makes awesome bubbles. (And of course, a bit of glycerine is a great help to a good bubble solution as well.) I would love to know of other good bubble solution soaps that people use, or better yet a homebrew solution recipe.