Take a look at the NRM's latest online exhibition: Caution! Railway safety since 1913.
It was based on research by Mike Ebester, a senior lecturer at Portsmouth, who specializes in the history of health & safety. With his expertise and interest in railways (both his MA and PhD were in railway studies), this exhibition has academic clout behind it, yet has been presented in a very accessible way for the general public. Also of note is the decision to put the exhibition online. This allows people from around the world to see it and also makes some of the NRM's archival material available to a much wider audience.
Academic work is increasingly expected to have public impact. Working on museum exhibits is a good way to do this. An important part of being a historian is translating research into a variety of forms: lectures, books, articles, theses and so forth. Museums offer yet another avenue for that hard-earned research material.