Here is a list of people who have told me personally that they would give me an employment reference if I needed one. If you need to know how to contact any of these people, please send me e-mail, letting me know who you are, why you need the reference, etc. (if I don't already know these things), and I will have them contact you, in the interest of their privacy.
Anyway, here's the list (in reverse chronological order, based on the last time they gave agreement, or alphabetically by last name in any cases where the dates are the same), with what they do, and the approximate date that they (most recently, if more than once) said I could use them as a reference: