Readernaut
I was surprised to see no results show up for the term “Readernaut” when I put it into my blog’s search earlier today. I like the service a lot and couldn’t believe I hadn’t recommended it yet.
So, without further ado, here’s what it allows you to do:
Share your reading experience by writing notes, tracking progress, and meeting fellow readers.
I’m using it to keep track of my reading progress with almost every book I read (Readernaut unfortunately does not work with books not available on Amazon) and to catch a glimpse at what others are reading around me.
You have access to my profile at http://readernaut.com/schrader/ and find out that I’m currently reading David Allen’s “Making It All Work”—a successor of “Getting Things Done”, of which you’ll know by reading my blog, I’m a fan.
Share what you’re reading and follow me 
If you like this post, please digg it — thanks!
About the Author
Additional comments powered by BackType
I didn’t try their competitors, but readernaut seems most “social”. They seem to have some performance problems though: Too aggressive caching and the search takes hours.
To all (German) students I can recommend my last read book “Uni-Angst und Uni-Bluff” in which Wolf Wagner describes German universities:
http://readernaut.com/books/3434461159/notes/
Regarding Performance Problems & Caching: Actually true. Everytime I update my progress I have to ignore the fact that my update isn’t reflected on the “Activity” page right away.
Irritating at its best.