Amazon gives you a way to do this, lend an ebook to someone for x days. Problem is that the publisher set the terms for lending, meaning they can disable it altogether and they can set other limitations such as time limits and that you can only lend them out once etc. Which is kind of sickening.
But I can understand what they are afraid of, in a digital world it would be trivial to set up a lending service letting users automatically borrow books from each other. But really, I should be able to lend out to my family, friends and colleagues for as long and often I want (that I can't read it myself while it is borrowed and that I can only lend it out to one person at a time are very reasonable limitations that mimics physical books).
http://www.cio.com/article/696062/How_to_Share_Amazon_Kindle...
But I can understand what they are afraid of, in a digital world it would be trivial to set up a lending service letting users automatically borrow books from each other. But really, I should be able to lend out to my family, friends and colleagues for as long and often I want (that I can't read it myself while it is borrowed and that I can only lend it out to one person at a time are very reasonable limitations that mimics physical books).