If you've ever been to a shiur of mine, you know that I generally try and hand out source sheets to the shiur with copies of the original text as it appears in book form. (Some people just copy the text from a CD, but I feel that the form factor of the text is important, and contributes significantly to the learning experience.) So I faithfully scan the books, edit the scans and paste the material using Microsoft Publisher. I once even gave a short presentation on how I make my sheets at the Soloveitchik Institute (a"h) for a bunch of rabbis. At the Tzohar Conference last week a fellow participant told me that since then he's been making his sheets that way, and he always thinks of me because of it.
I recently discovered a new tool that has the potential to save me a ton of time. HebrewBooks is a website that has put literally thousands of old seforim - most of which you've never, ever heard of - online and available for download. It's truly incredible. But they also helped me quite a bit, because they recently added a shas section which has the entire Shas available online both for reading and download. If you learn daf yomi and need a quick printout of today's daf, they've got you covered. If you're giving a shiur on masechet Brachot, and need a perfectly scanned copy of the entire masechta with the Rosh, Rif and Rabbeinu Yonah (like me), you can do that too. Oh yes - it's also totally free.
My chavruta and I were learning recently and we came across a reference to a Teshuva of Rav Moshe Feinstein in Igrot Moshe. I was about to get up to get one from the library when he opened his laptop, and quickly opened a pdf file with the entire eight-volume work. When I asked him where he got it from, he answered me in his heavy Hebrew accent: "Hebrewbooks."
You know how we're always complaining about how terrible the Internet is, with the pornography, violence, gambling, and pretty much everything else. We're right too. Except we don't often acknowledge that there's another side too. The Internet also has amazing learning sites (like, ummm, I don't know...spolter.net?), where you can download thousands of shiurim for free, and even learn the entire shas.
It's not that the Internet is bad. It's neutral. The trick is learning (and teaching our children) how to use it, and how to have the self-control to know where to go, and where to stay away from.