Can the Nook 3G/Wireless be used in Italy, primarily in Venice and Rome? I believe books cannot be downloaded, but can the Nook be used to view Rick's books if they were downloaded in the USA?
I can speak to the Kindle, which I believe has the same challenges as the Nook. Download everything you think you need in Europe before you leave the US. Make photocopies of key maps because the e-books are not great for maps. I made a folder for each city and enclosed the maps I needed from each RS book as an adjunct to my Kindle. I also book marked items I knew I wanted to reference quickly so I had a sort of custom index which cut my search time down a lot.
Anything that is on your Nook when you leave the US can be viewed in Europe, anywhere in Europe. You are correct, that you cannot download new materials/book overseas. Just make sure that if you purchase on your computer, that you update and download (Check for new B &N Content) on your Nook prior to leaving US soil. Even if you bought on your Nook, go to "check for new B & N content" and updated prior to leaving on your trip. I took my Nook to England and France in October and enjoyed hours and hours of reading without dragging the 6 books i read in the almost 3 weeks I was overseas. Make sure you have a plug adapter so you can charge your Nook, and certainly don't forget the power cord, and maybe a light for night time reading.