Here is a page I've been meaning to link to for a while, the online record of Hieromonk Alexander Golitzin's interdisciplinary seminar on the Jewish Roots of Eastern Christian Mysticism. Some of the work here is meant for the specialist, other parts can be read profitably by anyone. Father Alexander's two part essay, Liturgy and Mysticism: The Experience of God in Eastern Orthodox Christianity is a good place to start. (Requires the Adobe Acrobat reader.)