Ever since I first tested the Amazon Kindle as a speaking tool,  I knew it had great value in addition to its book-reading capabilities.  But price remained a barrier for many speakers.  This week, Amazon announced new features and far lower prices that make the device the least expensive e-reader out there--and worth a second look if you are a frequent speaker.  Here's how I see the Kindle's uses, through the eyes of a speaker. It's: