Hmm, I guess a good start would be to listen to some King Crimson material..."Court of the crimson King", "Discipline" and the new album "Power to Believe" should give you a good indication of Fripp as a prog player.
His solo things tend to be rather bizarre, especially the soundscapes albums, where it's just him, the guitar, and an insane looping rack, creating ambient textural music. There are also other solo things he has done that I haven't heard. A good website for some samples would be:
http://www.disciplineglobalmobile.com/index.htm
