How to fix it for Firefox 3.6 Rated 3 out of 5 stars
This is a great add-on but it seems to have stalled in development. In particular it does not work for Firefox 3.6. Here's how to fix that.
You can get version 0.72 from http://www.bookburro.org/ Unfortunately it set for up to version 3.5 but you can change this in the file install.rdf. XPIs are zip files so you can unpack and pack in a normal way. In install.rdf you need to change em:maxVersion to say 3.6.* instead of 3.5.*. Then pack it up again as a zip file and rename it to an xpi file. Then you can install it in 3.6.
The source code for this open source project is available at http://github.com/anotherjesse/bookburro so if somebody else wants to work on it, that's where it is. The author has not done anything since October 2009.