These MLPs can enable you to generate lots of passive income.The dividend yield on the S&P 500 is currently around 1.2%, which is near its all-time low. As a result, it's getting harder to find stocks with attractive dividend yields. However, there are some enticing income opportunities if you know where to look. For example, several master limited partnerships (MLPs) offer much more enticing yields these days, including Energy Transfer (ET +0.91%), Enterprise Products Partners (EPD 0.25%), and MPLX (MPLX + ...