TwitPic lets you share photos on Twitter. You can post pictures to TwitPic from your phone, TwitPic’s API, or through the site itself. There are also popular twitter clients that have built-in support for TwitPic.
2) TwitrPix (discontinued..)
TwitrPix gives you, your friends, family and co-workers the ability to upload and post photos on Twitter using your mobile phone, desktop web browser or by email. Along with a photo of your choice, you can include a message that will get Tweeted with it.
3) TweetPhoto (discontinued..)
TweetPhoto is a real-time photo sharing platform for the social web. Instantly share photos on Twitter, Facebook, and more. Once you login with your Twitter username and password, your TweetPhoto account is automatically created. You will then be able to instantly upload photos on the website, via email, or through your mobile phone and share them with your Twitter and Facebook friends.
4) Smug Mug
SmugMug is an interactive application that allows you to share images and photos on Twitter, FriendFeed, Facebook and Tumbler. This app uses Twitter’s secures OAuth login Process to allow you to conic to Twitter and post relevant images and photos.
5) flick.to.twitt (discontinued..)
flick.to.twitt is a service the lets you post a photo to your Flickr account and automatically announce it on your Twitter account. This enables you to use Flickr as a photo sharing option for Twitter and keep your pictures all on the same place.