I don't know how I found it, but some years ago I discovered the excellent site, KosherTorah.com, which is managed and administered by Rabbi Ariel Bar Tzadok. Each week or so, Rabbi Tzadok emails a newsletter, and almost always, the newsletter is about Jewish mysticism. I am 99% of the time in over my head when I read his newsletters and I excitedly look to the day when I will have a better understanding on the material that I read and pretend to understand. I never heard Rabbi Tzadok speak, until today, when I visited IsraelNationalRadio.com and read that Rabbi Tzadok was a guest on Tamar Yonah's radio show. Here's the link. You can Listen to the Radio show, or you can download the file and listen to it later. I highly recommend either one.
An excerpt about the Radio show from IsraelNationalNews:
Mystic Rabbi Ariel Bar Tzadok joins Tamar and explains the mysteries of Purim. Why isn't G-d mentioned in the Book (scroll) of Esther? What exactly WAS the miracle of Purim? How do we learn about redemption from this holiday? Plus: The Lost Tomb of Jesus? - How can we know if these bones are truly those of the historical figure? What would it mean if it were? How should the world react to this? Listen Now or Download.