Just in case some non-English speakers might be interested, this is (almost) a cut-n-paste from the PRS-505 Dev Corner.
Attached here is the 5-language localization package (via U.F. v 2.0) for Sony firmware version 1.1.00.18040. The menu language switches between English, French, Spanish, German and Russian.
Update: The menus for PRS-500 are also localized with the same languages
If someone prefers a ready-made image with built in Cyrillic-enabled Unicode fonts (the default Sony fonts only supported Western European characters), you can download it
here.
To toggle between locales go to Settings->About (or whatever it is in your language) and press 1.
This update also enables the clock (switch on/off in Settings->About by pressing 0), joypad paging forward in books, shutdown by holding Enter.
Any questions/problems - post
here.
Known issue: some (few) messages are not translated - either because I was lazy, and I thought in case of emergency they could easily be understood in English without translation, or because I haven't yet figured out how to get to them.
Thanks to
zelda_pinwheel (French),
ovejadolly (Spanish) and
Dominik (German) for providing translations!