Do you like to read background details related to the books you own? If so, then you've probably gotten a lot of enjoyment out of the Kindle's XRay feature.
If you haven't seen it yet, here's a brief description. XRay the name for one of the sidecar files for Kindle ebooks. This particular file contains content pulled from Shelfari like summaries, character details, locations descriptions, and the like. The file varies in the quality and size of the XRay file depends on what users upload to Shelfari.
And until I found this tool I thought that this feature was only available for the ebooks sold by Amazon. But now you can make your own. Or you can try, at least.
I think this is very neat tool but I also think it's too much work (for me). I tried to get it working on a number of ebooks and I failed every time. To be fair, some of the ebooks I tried are older copies from Baen. They were pretty sloppy back then about entering all the metadata, some of which may not have been invented when I originally downloaded the ebook. On the other hand I also tried to get it to work with the first Harry Potter ebook. I failed.
But if you want to try it, you'll first need install MobiPerl, which you can get here. You might also want to get the Windows GUI program; this saves you the work of running MobiPerl from the command line. After you have those tools downloaded, go the Xunwang website and follow the instructions there.
P.S. Note that while I'm not going to bother with this, I think publishers should at least consider it. If you sell your own Kindle ebooks then this is a tool you should learn how to use. It adds value to your ebooks and your readers will appreciate it.