Well, I didn't have time to add Spanish and German locales yet, so in this version I just have English, Russian (requires Russian-enabled Unicode fonts) and French. I will add German and Spanish in the next few days.
This is in
Universal Flasher 2.0 format, and the locales are only enabled for Sony firmware version 1.1.00.18040.
To switch to French locale go to "Settings->About" menu and press 1. The locale is going to toggle between English, French, etc., so if you decide that you didn't like French, you can switch back to English. If you switch to Russian and you don't have Cyrillic fonts, you will have to navigate the menus from the memory - you will get a bunch of empty squares instead of letters.
When you have switched to French locale, go back to the menus, and they should be in French.
This update also enables the clock (switch on/off in Settings->About by pressing 0), joypad paging forward in books, shutdown by holding Enter.