I'vRead is a service for keeping track of what books you've read. Seems simple, but it can be rather useful for those of us obsessed with reading like myself. Its web site offers the service for free, and using it is already pretty simple. There isn't even another account to register for. All a user needs to do is add a specific tag, @ivread, to a Twitter post mentioning the book. It allows for some basic searches of the data on their website, but the I'vRead API is where the service really shines.
I'vRead is based on a Japanese service that does the same thing, called Yonda4. The same API calls work for Yonda4 as well, so both services could be integrated into the same webapp with almost no extra code. Also, it's pronounced "yondayo", as yo is one of the ways to say 4 in Japanese.
From the I'vRead site:
I'vRead(ivread.com) is a service to record your books reading history. All you need to do is just to tweet the book name to @ivread on twitter
ivread.com does not require user registration. twitter users can just tweet to @ivread and voila, it's done! We use "Twitter as a Platform(TaaP)". If you do not have a twitter account yet, please register on twitter site
You may set your Amazon Associate ID on your personal book history page. Amazon links on the top, rankings and each book page have our associate tags, and the income will be used for site management and enhancement.
The API is a RESTful service, formatting responses in JSON or RSS. It allows developers to either get a list of recent posts from everyone, or a list of what a specific user has in their reading list. An interesting use of this could be a site including RSS feeds of the reading lists of either one's friends, or a group of famous people one is interested in, if they start using it. The simplicity of this service just blows me away, as using it requires no more than a Twitter link. The API also has no API keys or anything, so again, no registering to get started.