The Linac Coherent Light Source or LCLS at Stanford is home to the one of the world’s first hard x-ray free-electron lasers (XFELs), which enables whole new classes of experiments on biological structures, as well as in many other fields. LCLS delivers x-ray pulses 120 times a second. The pulses can be as short at 10-14 seconds (10 femtoseconds), and contain about 1012 photons. These pulses can freeze molecular motions like a flashbulb, and are so intense that they can produce observable scattering from nanocrystals 1000 times smaller in volume than those we use today. The talk will briefly discuss how XFELs work, and will present vignettes of new and work using the LCLS on biological systems.