Something I mentioned about the Kindle 3 was the paid wireless transfer program. At the time I didn't have a clue how it worked but after a few weeks I've got the scope. Here it goes. Only 3G users need worry about paying any charges, and only when they're using 3G. You get charged by the megabyte and rates vary upon where you are located around the world. Books usually have a flat rate on data transfer charges, and documents (explained later) are charged by the amount of data.
Amazon has every Kindle user set up with a kindle email box. You can email documents to the box with the word "convert" in the subject and Amazon will (for free) convert your document into a Kindle specific PDF document. If you don't include the word "convert", they'll just forward it as best they can straight to your Kindle the next time it syncs.
The document formats Amazon accepts are "Microsoft Word, PDF, HTML, TXT, RTF, JPEG, GIF, PNG, BMP, PRC and MOBI" (from Amazon's Kindle Document Services page). The advantages are many. Regular PDFs display perfectly fine on the Kindle, but they don't render in a way that allows you to change the text size. So if you have Amazon convert it for you, voila! A PDF with 7 text sizes and zooming. Nice. Beyond that, the other files aren't supported so while it'd be nice to be able to "just open" a Word document like on a tablet, the ability is still there.
One example of how I've used the PDF conversion is I have a lot of tech manuals in PDF format. I've sent them to Amazon to convert and now I have them on the Kindle in a searchable, resizable format. The conversion was done in under ten minutes, on a file that was about 14MB. Not too shabby (and free).
I've found a great website called Instapaper that has a "Read Later" bookmark that allows me to run a tiny script on any page I'd like to, well, read later. Which is great for me since I read a LOT of content in the course of a day, but I don't always want to read it now. In fact, I get annoyed if I miss an article or have to pass something that I would like to read but don't have the time at the computer. I click "read later" and then later that week or whenever I sync, I can look over the articles I would have missed otherwise. Some may say I should use one of the many RSS forwarders, but that's not for me. Too many stories, I don't want to sift through them on my Kindle. I use Google's Reader aggregation and sift from there.
You 3G customers may be reading all this and saying "Well, that's all well and good but how much does it cost us.". Well, if you don't need it right away, just sync over wi-fi and it's completely free. You can find the 3G fees here. Amazon will only allow documents from approved email address to access your Kindle account. So don't worry about getting random spam. If you don't specifically add an email address, it cannot access your Kindle.
As a last line of defense, you can send your documents to one of TWO different Kindle addresses set up just for you by Amazon. One is
You can access all of these from your Kindle management page (linked to your Amazon account). One other great feature is the ability to limit the cost per transaction so that you don't accidentally overcharge yourself.
There you have it. Relatively easy document conversion, easy cost control and insane battery life. Now that' I've made a fair assessment, I can honestly say that the Kindle 3 is the clear winner over the better e-reader. At least for now.