I have created a small script allowing you to generate an epub / PDF with all hosts informations next your itinerary.
It use you warmshowers login & password and a GPX file, and it retrieve hosts in a square a 5 kms and generate an epub with all hosts informations.
After you can print it, or better, carry it with you in you ebook or smartphone.
The script isn't hosted yet, I have some server problem, but if you are aware about script, php & cie, you can download it on github : https://github.com/ChoOo7/warmshowers-to-pdf
Feel free to ask for new functionnality or make pull requests !