Italian Hand Gestures
Comedian Russell Peters remarks [note: language not appropriate for kids in the video] that "every word in Italian has a hand signal that goes with it...it's like [Italians] all used to be deaf at some point." Indeed, the language is spoken as much with the hands and face than the lips. Gli italiani parlano con le mani. The following is a summary of some of the main gestures--note that for most of them, if you do it with both hands, it is a stronger version of the same gesture.
Warning: Many of these gestures can be vulgar; stars indicate how much (* = off-color, ** = somewhat offensive, *** = extremely offensive)
Resources for Learning More About Italian Hand Gestures
Eurocosm's Italian hand signals page is the most extensive and descriptive, but it is completely in Italian.
About.com's Italian Hand Gestures page has a long list but the cartoons are not always clear and some are not very useful (e.g. you can figure out "Andiamo a dormire" by yourself)
Marcello Mastrantonioni's video, with his over-the-top caricature of Italian machismo, includes some hillarious random gestures.
La mimica degli antichi investigata nel gestire napoletano is a classic, scholarly book about Neapolitan gestures; also see an English translation with commentary by gesture expert Adam Kendon.
A clip from Boy Meets Girl has a lesson in Italian gestures starting about a minute in.
Some videos that include language not suitable for children but nevertheless informative/interesting/entertaining are Paolo Tosolini's useful and quick introduction, an Italian exchange student giving a crash course in front of the Eiffel Tower, and a crazy one with a wifebeater-clad southern Italian guy giving a very animated performance.
You can also check out Neapolitan-specific gestures on the Portanapoli webpage.