Many LaTeX book/article/conference templates, esp. those from the last century ;-), still use old-school indentation. And since I am finally starting to put my PhD thesis work into a real thesis document I was looking for a way to automate the cumbersome manual work I had done previously.
Here is my current solution (based on this TeX answer):
This work nicely for the AMS book template. If you use LyX, as I do, then just add this to your LaTeX preamble in the document settings.