Information originally provided by Brian Milner.
"The Unbelievable Bubble Book" (by John Cassidy, Klutz Press, ISBN 0-932592-15-5) is a good reference for the bubble arts. It comes with a "bubble thing" attached to it, which can be used to blow extremely large bubbles (typically 4 feet across or more!). It's great fun, and really draws a crowd when you're doing street shows.
The bubble recipe in the book, originally developed by David Stein, calls for 1 cup of washing up liquid [Americans, read "dishwashing detergent"(?)], 10 cups of cold clean water, and 4 tablespoons of glycerine from the chemist [Americans, read "pharmacist"]. This is the basic formula for big, long-lasting bubbles. Combine ingredients in a clean pail...
Any hoop shape will generate bubbles -- the ring pull of a coke can, the plastic thing that holds a six pack of beer together, a wire coat hanger, a cheap bubble juice bottle wand, a tin can with both ends cut off...