I've recently been playing with an e-book management program called Calibre. Now I don't see how I lived without it.
Calibre is an open-source, cross platform program that lets you manage your e-library, convert documents and e-books to different formats, download news feeds, and sync everything with your Kindle.
As if dragging and dropping files to your Kindle's "Documents" folder weren't already easy enough, Calibre makes it even easier, even giving you a choice of sending a document to your Kindle memory or your SD card (for K1 users only, obviously). It makes conversion a snap too for those documents not already in Mobi format.
Calibre's best feature is "Fetch news," which lets you download popular news feeds and then transfer them to your Kindle. There are a lot of fantastic feeds available, such as The New York Times (registration required), The Economist, and Wired magazine, but with a little work you can add your own custom feeds as well.
You can schedule automatic downloads of your favorite news feeds, but for that to work you have to leave your computer on and Calibre running. I prefer launching Calibre and manually downloading the feeds when I want them.
So far I've downloaded issues of the NYT and The Economist for my Kindle and they look great.
The program is easy to use but there is a manual on the website in case you get stuck. The one roadblock I ran into initially was not noticing that Calibre has the preferred e-book format set to EPUB by default, which sadly doesn't work with Kindle. So I when I tried to transfer my first batch of news to my Kindle I got an error saying no valid device was connected. Once I realized my mistake and switched the preferred format to Mobi it worked like a charm.
I can't recommend the program enough for Kindle owners. It's a fantastic way to get news to your Kindle -- for free -- and an all-around good tool for managing your e-library.
Calibre is free but they accept donations.