Amazon's Kindle bookstore is great, but did you know that the Kindle can help you read more than just books?
You actually have a not-so secret email address as a Kindle user, whether you use a dedicated Kindle device or use the Kindle software on a smartphone or tablet.
If you send a PDF to your firstname.lastname@example.org, the next time you load up your Kindle, that document will be ready to sync to that device. You just need to verify the sending email address, via your Kindle account manager — so, not just anyone can send files to your device.
Handy for reading a long document or a free PDF book on that eye-friendly Kindle screen.