While not strictly about Galatians, E. P. Sanders was presented with a Festschrift at SBL this past week. More information is available from the publisher, although for a list of articles you must head over to WorldCat.
Redefining First-Century Jewish and Christian Identities: Essays in Honor of Ed Parish Sanders. Edited by Fabian E. Udoh, et al. Notre Dame: University of Notre Dame Press, 2008. 448pp. 0268044538, 9780268044534.