PostgreSQL docs in ePub format

I've noticed that the documentation for PostgreSQL comes in two formats:
HTML and PDF. This is great if you have a full sized screen and an
internet connection. But what if you have a device that cannot correctly
display in standard page sizes (US or A4)?

I want to make an attempt to take the DocBook/SGML text that comes with
PostgreSQL and produce an ePub file. However, I have no experience with
this. I would like to get together with other like minded PostgreSQL users
and produce something useful.

If anyone from O'Reilly Media is on this mailing list please let me know
how you do this, i.e. what tools you use and what commands you run to
produce the ePub books that I buy from you.

Thanks and regards,

Edward Hooper