There was an excellent documentary about his life on BBC4 some time earlier this year.
Not only was he a gifted guitarist but he was the first person to create multi tracking and was always looking for a way to get better electronic sounds. His early recordings with Mary were often done in various rooms in his house and in hotel rooms as he strived to develop the best sounds.
There seems to be some dispute as to whether he did invent the electric guitar before anyone else or not but he definately helped to develop it and to make it popular.
He realised that you needed something that was quite dense to get more sustain and if you feel the weight of a Gibson Les Paul you soon realise how much heavier they are than most of the other top brand electric guitars.
He came across as a really nice guy too.