A few years ago I discussed the problem of finding duplicates in a stream of numbers. Jaikumar Radhakrishnan gave a talk here showing how to find a duplicate in randomized poly-log space using only one pass through the data.
Also parallel repetition is making quite a comeback because of its connections to PCPs and the unique game conjecture. Raz recently showed limitations on parallel repetition, basically the error goes down at least quadratically as bad as you like. Thomas Holenstein talked about his proof that gives cubically as bad and Oded Regev talked about the general connections between unique games, parallel repetition and semidefinite programming relaxations.
These were just a taste of the interesting stuff discussed this week. Talks, abstracts, slides and more here.