, an official Twitter client for Windows, is the most popular one but there are also some worthy alternatives like Seesmic Desktop or the more elegant MetroTwit.
Echofon is powerful Twitter App for Windows Desktop and gives access to all the features of Twitter. Echofon consumes relatively less memory and doesn't occupy the whole desktop screen. You can sync Echofon with your iPhone painlessly.
This Echofon Twitter app is compatible with iPad, iPhone, Firefox, Mac and Windows. You can access your Twitter list, saved searches, @ mentions, trending topics and even messages in the same window.
With this app you can configure multiple Twitter accounts. It supports Keyboard shortcuts. You can simply add an Image to your tweet by simply using Ctrl + I.