I'll nominate Soul Identity by Denis Batchelder
You can't take it with you...but what if you could? Most people believe their souls outlive their bodies. Most people would find an organization that tracks their souls into the future and passes on their banked money and memories compelling. Scott Waverly isn't like most people. He spends his days finding and fixing computer security holes. And Scott is skeptical of his new client's claim that they have been calculating and tracking soul identities for almost twenty-six hundred years. Are they running a freaky cult? Or a sophisticated con job?
Scott needs to save Soul Identity from an insider attack. Along the way, he discovers the importance of the bridges connecting people's lives.
Here is my brief review on my blog?
I think you can also get this at Smashwords... not 100% sure.