Sean wrote a wonderful post about the recent measurement of the anisotropies in the cosmic microwave background from the South Pole Telescope. I am so impressed by the data. To give you a visual impression on just how dramatically the measurements have improved, I've dug out an old plot from 1999. (Note the square root in the vertical axis though.)
Fig1: CMB power spectrum, 1999, data from Python (star) and Viper (box). Image source.
Fig 2: CMB power spectrum, 2012, data from WMAP7 and SPT. Image source.
For more information about the CMB anisotropies, please refer to this or this earlier post.