Abstract: SLAC fixed target experiment E158 has receintly measured a tiny parity-violating asymmetry in electron-electron (Moller) scattering.  A 128 parts per billion (ppb) asymmetry was measured with an uncertainty of 18 ppb and leads to the most precise to date determination of the effective weak mixing angle at low energies. A comparison of our results with the electroweak measurements at Z pole establishes the running of sin^2(theta_W) with almost 7 sigma significance. In this talk, I will describe the experiment, its results, and implications, and will also mention unexpected spinoffs, including the first observation of the spin-orbit interaction in Moller scattering (a second-order QED effect) and some insights into proton structure.