I just found this great site!
If the link doesnt' work here is what it said (there is even more on the site).
WHAT IS SKIFFLE?
The term "SKIFFLE" has a variety of meanings but always refers to informal, good time music, usually using home-made or improvised instruments such as the washboard, wash-tub or tea-chest bass, kazoo, cigar-box fiddle, comb and paper etc.
Depending on your age and country you might define skiffle as:
1) The spasm bands, usually children, seen on the streets of New Orleans around 1900.
2) Rent-party music in 1920s and 30s USA involving piano, guitar, fiddle, but rarely the washboard.
3) The jug bands of Louisville and Memphis 1920s and 30s.
4) Novelty Jazz Bands of the 1940s and 50s using clarinet/sax mouthpieces on bamboo or wooden pipes, plungerphone, funnel with trumpet mouthpiece, washtub bass etc.
5) A mixture of USA folk music, tin-pan alley, and music-hall played as pop music in Britain in the late 1950s, typically using guitar, washboard and tea-chest bass. Lots of famous British rock stars got started by playing in skiffle bands, e.g. the Beatles, Van Morrison (who made a skiffle CD with Lonnie Donegan in 1999) Although they will probably have never heard of Leadbelly or Woody Guthrie, for a lot of British people over a certain age this music is part of their pop music nostalgia.
6) Current bands playing jug-band, Leadbelly songs etc. or "British" skiffle i.e. songs recorded by British artists in the 1950s, but all generally copying originals thus extending the life of this music
7) Current bands making their own music or adapting popular songs so the music lives and changes
The word "SKIFFLE" was probably first used by pianist Hersel Thomas (who died in 1926) to describe the music played at a house rent party (also called "skuffle" music). A record called "Hometown Skiffle" was released in 1929 featuring featuring Blind Lemon Jefferson, Blind Blake, Will Ezell, Charlie Spand, The Hokum Boys and Papa Charlie Jackson.
"SKIFFLE" was later used to describe American black folk bands who mostly had to improvise traditional African instruments by using household implements. The bent sapling with cord tied to a skin over a hole in the earth became the washtub bass. (Tea-chest in UK). The gourd became a jug and the scraped ass's jaw became the washboard. The kazoo developed from an African instrument using an animal skin as the membrane (often built into a mask and used for religious ceremonies).