You can read opinions about pickups from the large Harmony Central Guitar: The Electric Guitar Pickup Database. Seymour Duncan's site includes an interesting chart of pickup characteristics such as pickup resonant frequency, which I haven't seen elsewhere.
A Kettering University by Dan Russell site with Vibration and Waves Animations can help you understand what pickups are supposed to be doing. It was mighty swell of the people at Gibson to fund the modal analysis of the Gibson Hummingbird. I also like the Vibration of a Fixed-Fixed String analysis.
There are probably still plenty of students who struggle to study and play guitar at the same time. At Duke they can find an interesting research topic in Physics 36 / Music 36 Handout 9 called "Pickup Placement and the Vibrating String."
I wouldn't want to try to maintain a list of Guitar Builders and Repairers. Keeping it current would be too difficult! You would need to keep up with hundreds of links like these:
Joe Paradiso's site on Electronic Music Interfaces is often plagairized and seldom quoted. If people want to use the benefits of MIT research, they ought to at least write a footnote!
Someday all pickups might use Audio Optics.
You can use .wav files on you computer to manipulate digitized sounds.