I am pretty sure that when people will talk, say in the year 2100 or 2200, about the early years of the 21st century (and actually also about the last days of the 20th century), one of the key developments they will mention is the move from books to eBooks.
Right now we are in the middle of this development, indeed revolution, and so we don't see how huge it really is, but it is huge.
Twenty years ago in a normal sized town, one had access to maybe 40,000 books in normal bookstores. Nowadays its closer to two million at one's desktop.
Of course there has been a parallel change with academic libraries and online research materials.
At the end, IMHO, this is what will eliminate ignorance.
While there are other noteworthy endeavors, such as Project Gutenberg, and Google Books (quite limited where I live), I think Amazon is the main force behind this revolution.
Of course there are problems with Amazon, such as tax problems, this whole Hachette business, and other stuff, but all in all I think they are a force for the good.
I only wish they would pay their employees a bit more...