David Gilmour and Robert Fripp
http://www.youtube.com/watch?v=P5XSrauxPOw David Gilmour forms a chord by moving his fingers in reverse direction on the neck.
http://www.youtube.com/watch?v=r7P4dt4G5B0 Robert Fripp playing a 7/8 Time signature with the rest of the band in 4/4.
both are unique and talented guitarists, those are my favourite examples of their work.