Social Protocols
The anatomy of a Twitter status update, at just 144 characters, makes it so easy to manipulate, store, process, and parse. The at replies feature in Twitter makes it a two-way communication medium. The hashtags adds context to the million of tweets running through the system. And the millions of users are finding new and dynamic ways to interact with the system. Twitter is like a web version of the walkie-talkie, some might say that it is the web version of a party line. All of the simplicity, momentum, and openness makes Twitter an interesting platform to play with and develop new social protocols.
There are a growing number of applications that are built on top of the Twitter platform. The first incarnation of Twitter apps piggybacked on your Twitter credentials, including your username and password. These applications include Twitpics, StockTwits, and Twittervision. This is an insecure method authentication and Twitter has announced their plans to move to OAuth
Personally, I think there is a more organic and interesting way to interact with users on Twitter that is just gaining traction and that is via the at replies. Innovative and non-intrusive applications are using the at replies and hashtags as a social protocol. For example if you at reply wefollow with three hashtags it will index you on their Twitter directory under those tags as categories. At reply Mahalo Answers with your questions and they will reply back with an answer. You can also have your tweets read out loud on an audio stream when you at reply a message to No Agenda Stream. Send an at reply Ruby programming language expression to rubx will reply back to you the output value of that expression after the run it through a Ruby parser. All of this is done automatically and programmaticly.
If you want to get started writing your first Twitter application, here is a tutorial that will help you get started with the Twitter Ruby Gem.