Twitpic
One of the most popular twitter applications is called twitpic. As its name implies, the app lets a person share their photos on Twitter.
Sounds simple and indeed it is.
The service actually reached over 5.5 million subscribers as of November 17th 2009.
To use it, all you have to do is register an account. Then you can either upload your photo to their database, or send it to a custom email address via cell phone.
There’s room for a message to go along with your twitpic too.
And if you’re really bored you can watch the public stream of pics right on the sites mainpage updating every minute.