Originally, Sony wasn't very forthcoming with the file format so it fell on the community to create tools for translating content. Several good utilities now exist, but they tend to be pretty simple and the output can be rather lacking at times.
There is another solution - there is a commercial product from Canon called Book Creator that seems to be the official implementation of the .LRS/.LRX standard. There is even a fully function trial version that can be used for 1 year.
There are 3 things that suck:
- The program is Japanese only
- Canon pulled the download early in 2006
- It expires this month, and doesn't like to install anymore.