I'm porting FBReader to the lbook v3. You can try it by flashing the modified firmware. Here are the instructions:
* flash this fw: V3_20080129_LIB1503_2.zip
(this is the modification of the recent original lbook fw)
* create a directory in the internal flash named 'lib'
* copy this file into lib directory: libfb2.so
After that, fb2 and fb2.zip files will be opened with the fbreader plugin. Other formats supported by fbreader can also be viewed, but you need to zip them first and rename the resulting archive to *.fb2.zip.
You can also change some settings in the .FBReader/ui.xml file in the internal flash, here is my sample config: ui.xml
There is a possibility to hot-swap the fb2 plugin with just swapping the libfb2.so file in the lib directory. Here are the plugin from the original lbook fw: libfb2.so
and the new beta version of the same plugin: libfb2.so