The 2006 Alpheus Smith Lecture was held on Thursday, May 4 at 8 p.m. in 131 Hitchcock Hall. This year, the Department of Physics welcomed Wolfgang Ketterle, 2001 Nobel Laureate in Physics and the John D. MacArthur Professor of Physics, Research Laboratory for Electronics, MIT-Harvard Center for Ultracold Atoms, and Department of Physics. Streaming video of the lecture is available online. The lecture flyer is available for download here(PDF). More images of the results from BEC experiments are available at http://cua.mit.edu/ketterle_group/Nice_pics.htm