Have you looked at Plucker (http://plkr.org)? As far as I can tell, the only existing reader is for PalmOS; but it is an open, documented format, and it does have hyperlinks and images.
I had heard of it, but somehow forgot about it. Thanks for reminding me!
(Is it actually possible to run a server on a cell phone?)
If you can run Java and Python on it, why not run a server? :)