Yeah, great summary Matt
Here you can find additional infos on how creating "REAL" panoramic HDRI.
("How to create HDRI dome" tutorial is another explanation ... like the one from Matt (http://hdrshop.com/
Some really good and famous ones ...
Lots of them there ... no need really to create yours hehehehe.
These are also usefull (not relative to HDRI) but environments panoramas. With a bit of tweaking and toshop, I usually get great 360*360 to be used as backdrop (reflections) or just as environment background.
Some last ref I advise you.
It's mainly talking 'bout IBL New Maya7 Node and some plugs and additional tools.