Forum:
Conferences:

List of conferences on string theory and related topics

Strings 2011 in Uppsala
Various:

Andre Geim’s insightful speech at the 2010 Nobel prize dinner in Stockholm
Recommended online video lectures on physics and mathematics:
 IAS summer lectures on “Aspects of Supersymmetry” 2010

GRASP lectures on mathematics at the University of Texas

ArkaniHamed’s 5 “Messenger Lectures” (2010) at Cornell

Witten’s IAS lectures on string compactifications (2009): Part I  Part II

Kontsevich’s master class on wall crossing (2010) at the Centre for Quantum Geometry of Moduli Spaces, Århus University
QFT and String Theory:

Quantum Field Theory Program at the IAS: Fall Term  Spring Term (Very nice lecture notes on QFT and string theory)
Modular stuff:

Paul Garrett’s Page (Contains a collection of notes on various topics in mathematics, particularly related to automorphic forms)

James Cogdell (Lots of good notes on automorphic Lfunctions in connection to the Langlands program)

The collected works of Robert Langlands (Maintained by the IAS)

J. S. Milne (Remarkable collection of lecture notes in mathematics, notably group theory, number theory & algebraic geometry)