The Touch is too big to attach to most peoples' shoes (unless you are Shaq), but the Nano is juuuuust right....
http://gizmodo.com/5370274/stick-a-...and-a-japanese-man-will-use-it-for-upskirting
http://gizmodo.com/5370274/stick-a-...and-a-japanese-man-will-use-it-for-upskirting