Welcome to the Manualism Page!
Brought to you by Gaston and Purcell
Manualism is the art of producing music by squeezing one's hands together. It takes many years of practice and even then is still quite difficult to control. It may be one of the hardest instruments in the world to play. The number of people who are performing manualism on stage is extremely few.  Some people when they first attempt to play their hands are able to get squeaks and occasionally a low bass note.  Even these rudimentary (with the emphasis on "rude") aspects of manualism are difficult to achieve.   
Typically, the hands are positioned by cupping them together so that a tight air pocket is formed. The air is forced out between the thumbs which causes the skin in that area to vibrate. By controlling this vibrating skin, a manualist is able to make music.  It is probably advantageous to have wet hands when first attempting to play.
Some manualists produce the sound from areas other than between the thumbs.  Sound production at the area of the base of the thumbs is also possible and bass notes are typically made from the fleshy area below the little finger. These factors can make microphone placement tricky when playing in an amplified setting.
For a further description of how to play hands, please see www.handini.com
For a different type of manualism that involves blowing air into one's hands to produce music, please see Ben Brenner of The Three Tendons.
For further information regarding manualism, please see the Wikipedia page constructed by R.A. Wilson.
History of Manualism
It's anyone's guess as to how long manualism has been an art. The earliest recording known is by a gentleman named Cecil Dill who claims to have begun playing his hands in 1914. He stated that his hands were cold and he began rubbing them together for warmth. This enabled him to get sounds from his hands that eventually turned into music. The songs he was known for were "Yankee Doodle", and "Let Me Call You Sweetheart".  As it stands today, manualism is one of the rarest of the arts.
John Twomey is a manualist of note who has appeared on numerous talk shows in the past 30 years. His most noted song is "Stars and Stripes Forever".  Many have seen him on the Tonight Show, Merv Griffin, and Mike Douglas.
Recent manualists who have had national television exposure have included Jim Rotondo, John Stephenson, David Pearce, Mike Kieffer, and Al Fike. Additionally, R.A.Wilson has been featured on PBS's "Morning Edition", and is currently seen on TVLand's website. 
Gerry Phillips, of Troy, Michigan,  has a number of manualism videos on YouTube and other sites.  Also, Shane Ebert, of Fargo, North Dakota, has done some innovative work with rythmical manualism.  David Fast, a director of films, from Toronto,  plays his hands, having done recordings of the USA and Russian national anthems, among others.
Bruce Gaston of Gaston and Purcell was featured on worldwide television (CNN Jan. 31, 1996). He is known for his use of vibrato (the wavering of pitch that singers and other instrumentalists use) during note production. See Mr. Handman's latest video HERE.
The Four Squeezins are presently the only known manualism duo.  They have a number of videos on YouTube. 
Please submit knowledge of any other manualists in the world to handmusik.
Folks---Please remember:  manualism is so rare that it is always close to extinction. Therefore, it is on the Musical Endangered Species List.  Because of this it is important to be kind to manualists and let them thrive in their natural habitat (national television or radio).  Please report any mistreatment of manualists to P.A.L.M. (Professional Association of Licensed Manualists).
Mike Kieffer, AKA "Musical Mike" performed manualism on several of "Weird Al" Yankovic's songs and videos.

John Stephenson Appeared on the NBC's The Tonight Show with Jay Leno.

Sean Hulings performed the theme song to Indiana Jones, as well as some other extemporaneous numbers during a segment called "Tonight Show, Side Show" on NBC's The Tonight Show with Jay Leno.

Al Fike Inspirational speaker who has previously used manualism in his presentations.

Douglas S. Pearce performed the theme song to Jeopardy! during a segment of Stupid Human Tricks on CBS's The Late Show With David Letterman, August 29, 1997

George Lowe Voice of Space Ghost, whose manualism has been heard on several songs from Cartoon Planet, most notably "Don't Touch Me." At one time, he routinely appeared on The Regular Guys show on WKLS, encouraging people to call in their most challenging requests.

Cru Egeland (Spokane, Washington) - appeared on NBC's The Tonight Show with Jay Leno January 20th, 2006. Performing manualism songs "Happy Birthday to You", and "Axel F" from the 1984 movie Beverly Hills Cop.

Prince Adam, a former member of "The Aquabats", can be seen playing "Every Breath You Take" by "The Police" on the Serious Awesomeness! DVD.

Other notable manualists