gDiapers are the first hybrid diapering option - they are halfway between cloth and disposables, but the really neat part is that the disposable bit can be flushed or (if it's just wet or you're educated in what to do to safely handle humanure) composted. Another really nice feature of gDiapers is that they can be used as an all-cloth diaper, by putting various cloth options (doublers, prefolds folded into 3rds, spare flannel receiving blankets, etc) into the snap-in liner. They've only been available in the United States since November 2005, but are based upon a product that has been available in Australia for over a decade. On August 1, 2007 a new and improved version of gDiapers was released. You can find my side-by-side comparison and review of them via the link below.
The main website for gDiapers is www.gdiapers.com. They are also available for sale at various online and local retailers. Some online sources include www.babycenter.com and www.amazon.com.