Robert M Watson Jr
The first rule of IT club is don't talk about IT club - IHTBF
The short list (not in any particular order):
Donald J. Angier
The last 5 on the list can also be seen on Aiki Expo DVD's
Folks known to have hands on with members of the above list (not in any particular order)
I gleaned this from postings about Dan Hardens seminar work so I believe these folks have all been hands on with Dan Harden.
Marc Abrams NY
Rob Liberti CT
Tom Holz RI
David Orange AL
Greg Steckel PA
Jon Haas NJ
Jeremy Alhouse MA
For out in my neck of the woods William Gleason, Ikeda Hiroshi and Don Angier have or do give seminars at Aikido of Diablo Valley.
Feel free to add and send corrections!
Put me down... I've played with every one of those people except for Dan H, some of them on many occasions.