I've just discovered this great CagePiano app - it randomises some of Cage's typical prepared piano techniques and the notes onto which they are applied, and places them on a 6x5 grid. It's pretty fun to play around with and randomly tapping away at different sounds makes a refreshing break from writing solo piano music...here's a little demo!
As a relative newcomer to prepared piano, I've been digging Cage's Sonatas and Interludes for Prepared Piano (1946-48). Cage's three pages of instructions for the positioning of forty-five various screws, bolts, rubbers, plastic and an eraser offer up a smorgasbord of new sounds, and, for me anyway, inspire some fresh compositional ideas.
French pianist Benoît Delbecq utilises some of these techniques in his remarkable solo record Circles and Calligrams (2010), fusing a colourful mosiac of prepared sounds with intelligent, exploratory free improvisation. On the second track, Ando, Delbecq flawlessly maintains a hypnotic left hand ostinato containing three separate rhythmic and sonic motives while dancing between chromatic, angular lines and soft, lush chords and further prepared piano sounds in the right hand solo. Later in the record, Fireflies offers a slightly more rhythmically energetic rendition of the same sort of techniques.