We use tracks (p > 1.0 GeV/c) in each tower to determine the ADC value of the MIP peak to get a relative energy correction for towers at a particular eta.  (see mip.pdf)

We then apply tighter cuts to select electrons and look for the p/E peak in each of 40 eta-rings to get an absolute energy correction.  (see electrons.pdf for preliminary plots using ~1/2 of available statistics)

There is still much QA to be done and systematic effects to be checked, but the two documents here show the current progress towards the Run 11 gain calibration.