Update: This whole post has just become irrelevant. I put the polish fonts into the reader, which turned out to be a simple task - uncompress cramfs image, replace original fonts with your own, compress again and update Reader sw. All nicely described here. No need to embed fonts anymore (at least until new Reader update comes out)

A couple of weeks ago I bought a Sony Portable Reader. The device is being sold on the other side of the big pond, so it doesn’t quite cater for the needs of us lowly Europeans, needs as frivolous as non-ASCII characters.

Well, things are not as bad as they sound, the Sony PRS-500 supports embedded fonts. By storing the fonts within a file, I could get all the ogonki that I need. Now, the problem is that whereas with only the built-in fonts, a page-turn takes, say, half a second, with embedded fonts, it tops at a couple of secs.
Having no diacritic marks spoils the reading experience, but so do the long page turns. For me the long page turns were the lesser evil, and I actually started to get used to them. There must be ways to optimize the page-turns, say by using a font that need less calculations than Times Roman, I suppose even using a sans-serif font instead, could save some milliseconds. I was planning to devote a weekend to experimenting, but then I realized, that there is a simple and instant solution.

It is not the page turn, that takes so long, but the whole data munging that precedes it - the long delay between pressing the button and the page turn. The only thing you need to do to solve the long page-turn problem, is to stop thinking about page-turning as an atomic operation.

TIP: To get a smooth reading experience with embedded fonts, just press the button a couple of lines (mileage may vary) before ending the page, so that you can finish the page, when the reader does its calculations. It is trivial, but it is against the natural p-book reading habits, so it requires some time to get used to it.