I live in Italy, where libraries don’t have that many English books! 😉 I used one in London during a trip, but most of my research is done online… through dedicates sites, such as Gallica (Bibliotèque Nationale Française from which you can download out of copyright texts.
But then I specialize in Middle Ages, so most of the studies are free downloads! 🙂
I just bought a Kindle, so I filled my PC with PDFs or TXT of things I wanted to read, and bought some dead tree books from Amazon or when traveling in English speaking countries…