Before arriving my prs700 I used to read on my Imate Jamin (AKA QTEK S900, HTC something). The usual 2.8" 320x240 screen.
I have not seen listed some handy programs that I liked very much:
1) Haalireader, http://haali.su/pocketpc/
, fb2 & txt reader, fast, customizable, I have read lots of really big books on it. There is a companion desktop program to convert html/doc/rtf to fb2, any2fb http://www.gribuser.ru/xml/fictionbook/
. Annotations, highlighting and double tapping dictionary pop-up available but in a special format.
2) Plucker and plucker desktop http://www.plkr.org/
. Wonderful, with this you can download any website (recursion depth customizable, restrict to a domain also available) and convert it to a single pdb with links & images. The reader acts like a browser, you can follow the links and going back or forward. FYI, I have read the whole Solar System Wikipedia article (50MB) with this. There is another desktop program for pdb generation, sunriseXP (perhaps you know this :-) http://sunrise.mobileread.com/
3) ubook http://www.gowerpoint.com/
. Very nice also, the best: you can use it with Webster with just a bit of tweaking. Double tap, look up and that's all. And if you don't know the meaning of some words in the Webster definition of a word you can search again the same way. Then there are handy buttons to go back to the book that you are reading.
Have a nice day!