Scratch (2001) is a documentary film, directed by Doug Pray, that looks at the birth and evolution of hip-hop disc jockeys (DJs), scratching and turntablism.
Interviewees include:

Grand Wizard Theodore (the inventor of the scratch)
Grand Mixer Q-bert
Grand Mixer DXT, Z-Trip
Mix Master Mike
Rob Swift
DJ Premier
Afrika Bambaataa
Jazzy Jay
Cut Chemist
NuMark
DJ Craze
DJ Shadow
DJ Babu
DJ Krush
Madlib
Peanut Butter Wolf

You can watch the whole [...]

In this video, Grand Wizard Theodore demos the Scratchophone.
The Scratchophone is a cool portable DJ instrument created by Thierry Alari. Here’s Alari’s answers to common questions about the Scratchophone:

Ammobox:lite is a free ensemble for Reaktor that promises to be “the shift in the way people will think about turntablism”:
With ammobox you can layer samples into a ’stream’ and scratch the stream, this allows for asyncronous sample triggering and layered effects that would be impossible otherwise. Microscopically you could say that ammobox is a [...]

Wikki-wikki-wikki! Students at Berklee College of Music are throwing their hands in the air. The school has announced that it will be offering the first college classes in turntablism, the art of scratching!
Boston’s Berklee College of Music, one of the leading institutions for the study of contemporary music, is breaking new ground in music education [...]