I received some complaints about the fact that some links in my books were dead by the time they were printed.
For the next book I am working on, I have proposed to my editor to set up a website to keep track of all references mentioned.
By using unique short ascii references throughout the book, it's easy to provide a simple redirect service to the target URL, and to fix it when it changes (just by setting up a mail alert if your redirect reaches a 404).
For example, if I am referring to mod_wsgi in my book, I can write this reference: #mod_wsgi, and provide a redirection to http://code.google.com/p/modwsgi into my website, through a unique, mnemotechnic permanent URL : http://ziade.org/urls/mod_wsgi.
This small service, à la Tiny URL is not a burden for the reader imho : he is using his computer anyway when he visits an URL mentioned in a book.
It's a simple idea I am sure a lot of people have thaught about before, but I fail to see it applied in the books I am buying these days. Is there any good reason I fail to see ?