"Send to Kindle" app

Amazon's Send To Kindle app is cool. It's for both PC and Mac. These are the main features from the Mac page:

• Send personal documents to your Kindle from your Mac.
• Drag and drop one or more documents on to the Send to Kindle icon in your Dock or launch the application and drag and drop one or more documents on to it.
• From any Mac application that can print, select the print menu and choose Send to Kindle.
• From Finder, simply control-click on one or more documents and choose Send to Kindle.
• Choose to archive documents in your Kindle library, where you can re-download them conveniently at any time.

That you can send from the Print command means that you get fully formatted PDF document for your Kindle app (best viewed on a color screen often), from any app with a Print command, it reads perfectly in the Kindle app, and it's like two clicks to send. So for example if somebody sends you a long Word document, and you'd like to read it on your iPad, on the sofa or the bus, it's five seconds' work to make that happen.