I’ve always run into a roadblock, though, when I’ve wanted to make one of my apps social. There aren’t any Ajax APIs I know of that can be used to share information in a way that isn’t vulnerable to spammers and other kinds of misuse, so I made one.
Twitblob is a simple cross-origin RESTful API that gives all Twitter users a small amount of public JSON blob storage on a host server. It also handles three-legged Twitter OAuth key exchange, allowing web pages to add social functionality with minimum fuss.
In a lot of ways, Twitter is a spam-resistant identity provider: its staff deals with the incredible hassle of keeping out malicious users, which makes it possible for me to offer 20k of storage to every Twitter user across any page on the Web without having to worry too much about misuse. So far I’ve used my Twitblob endpoint for a simple voting booth for my local Awesome Foundation chapter, as well as a prototype scheduling application for the 2010 Mozilla Summit. It’s been nice for adding social functionality to a page in a pinch.