Jonathan Richard Guy Greenwood is a BAFTA and Grammy-nominated musician and composer-in-residence for the BBC, best known as a member of English alternative rock group Radiohead.

Greenwood is a multi-instrumentalist, but serves mainly as a guitarist and keyboard player. He is the younger brother of fellow Radiohead member Colin Greenwood. In addition to guitar and keyboard instruments he plays viola, xylophone, glockenspiel, ondes Martenot (see below) , banjo, harmonica and drums. He also does work on the electronic side of Radiohead, working on computer-generated sounds and sampling. He was ranked number 59 on Rolling Stone’s “100 Greatest Guitarists of All Time”.

Jonny playing a tele [sunburst] using a lace sensor at the neck and two sensors as a humbucker, with pedal board [from left to right [visible: yellow Boss SD-1, white Boss LS-2, red Digitech Whammy(original), note the arm brace

Here is  jonny's Core Rig.  Jonny tends to experiment with alot of other instuments and peices of sotware also. He has been quoted saying "he doesn't really care about the equipment he uses, and said he'd just as much like to be behind a keyboard than playing guitar.  However its hard not to be impressed with the versatility of his rig.

Radiohead Pyramid Song Live

Electric Guitars

* Fender Telecaster Plus, with a custom cut-off switch and special rewirings made by Greenwood and Plank (Radiohead's Guitar Technician). This guitar is equipped with Lace Sensor pickups.

* Fender Telecaster Standard converted into a Plus which also has a custom cut-off switch and Lace Sensor pickups

* 1975 Fender Starcaster, with Fender Wide Range pickups, can be heard predominantly on Kid A and Amnesiac, it is used for most Kid A and Amnesiac he plays guitar on live, and a few songs from OK Computer.

* A Gretsch G6119-1962HT Tennessee Rose HT.
* Gibson Les Paul HD.6X-Pro Digital
* Gibson ES-335 (used on the acoustic Tour 2003)

After the release of The Bends, Jonny, went to a doctor because of pain in his arm. His aggressive playing style resulted in him wearing a brace on his arm. It has become a sort of trademark since. He says it doesn't bother him, "it's like taping your fingers before a boxing match".
Jonny currently uses Dean Markley Signature Series 10-46 strings.

Acoustic Guitars

* Martin D-35
* Taylor Big Baby (played by both Jonny Greenwood and Thom Yorke in pictures from Dead Air Space)

Amplifiers

*Vox AC30  used for clean tones.
* Fender Eighty-Five , solid state amp, used for distorted tones.

In the earlier years he used a Fender Twin Reverb for clean tones. He recently replaced the Deluxe 85 with an Eighty-Five.

Current Effects Pedals

* Marshall ShredMaster
* Digitech WH-1 Whammy
* Demeter "The Tremulator", older version of the Demeter TRM-1 Tremulator
* DOD 440 Envelope Filter
* Electro-Harmonix Small Stone
* Electro-Harmonix Poly Chorus
* BOSS SD-1 Super Overdrive
* BOSS RV3 Digital Reverb/Delay
* BOSS FV-300H Volume Pedal
* BOSS TU-12H Chromatic Tuner
* BOSS LS2 Line Selectors (3)
* Roland Space Echo RE-201 (Activated via Vox Egg Footswitch) Long discontinued, the Space Echo 201 has been recreated by Boss, in the shape of a twin pedal, the RE-20 Space Echo, which even purists say sounds very close to the original! For Jonny Greenwood fans, an essential - and a new classic in its own right!
* Mutronics Mutator (Primarily for studio use)
* Akai Headrush E2
* BOSS RE-20 Space Echo

Keyboards

* Analogue Systems RS8000 Integrator
* Analogue Systems RS8500X
* Analogue Systems French Connection
* Ondes Martenot
* Sequential Circuits Prophet 5
* Korg Prophecy
* Hammond XB2 Digital Organ
* Moog Rogue
* Mellotron M400
* Rhodes Suitcase Piano Mark I 73
* Fatar Keys CMS-161
* Upright Piano
* Celeste

The Ondes Martenot  French for "Martenot waves"; also known as the ondium Martenot, Martenot and ondes musicales) is an early electronic musical instrument, invented in 1928 by Maurice Martenot and originally very similar in sound to the Theremin.[citation needed] The sonic capabilities of the instrument were subsequently expanded by the addition of timbral controls and switchable loudspeakers. The instrument’s eerie wavering notes are oscillating frequencies produced by thermionic valves.

Keyboard Effects

* BOSS RV-3 Digital Reverb/Delay
* Electro-Harmonix Small Stone Phase Shifter
* BOSS FV300L/H
* BOSS LS-2 Line Selector
* Akai Headrush E1 or E2

Other

* Jonny uses a portable radio, specifically during the songs “Climbing Up the Walls” and “The National Anthem”
* Laptop Computer running Max/MSP (Used to process his guitar sound, such as in the guitar solo at the end of “Go to Sleep”. Also used to control electronic parts in live versions of songs such as “The Gloaming” and “15 Step”)
* Korg Kaoss Pad (for sampling, such as Thom Yorke’s voice in the song “Everything in Its Right Place”)
* Harmonica (for the song “I Am A Wicked Child” and on the Pavement songs “Platform Blues” and “Billie” from their final album Terror Twilight)
* Glockenspiel (for “No Surprises”, “Morning Bell/Amnesiac”, “Sit Down. Stand Up” and “All I Need”)
* Toms (he uses a pair of identical toms with two drum sticks for each hand. These are featured in “There There”, where most members of the band play percussion)
* He has recently been spotted with a banjo. The band played a sound check on their recent tour where Greenwood played the banjo on Radiohead song “I Am A Wicked Child”. Although other members of the band have said that banjos are “banned”, and despite Jonny’s constant attempts to include them with songs, they will not feature.
* Voodoo Labs Pedal Power units power all pedals.

Sources

http://en.wikipedia.org/wiki/Jonny_Greenwood
http://www.greenplastic.com/coldstorage/gear/jonny.php
http://guitargeek.com/rigview/510/