Hootsuite is a brand management service which publishes material not only on Facebook and Twitter, but also on other social networking sites like MySpace, Linkedln and Foursquare. You can also use this tool from your Android phone, iPhone or any BlackBerry device. You can use this service for free or pay a certain amount and have history and stats stored too.
TweetDeck is a Twitter owned, web application for maintaining your Twitter account. Users can have the program split into columns for displaying different features. You can also use it to follow tweets containing keyword mentions and searches. It was previously an independent app but due to its popularity, it later got acquired by Twitter.
Seesmic is known for its credibility and can help you manage a number of social networking sites. The advantage of using this application is that it has a well organized dash board and with it, tweets, retweets and direct messages can be sorted. You can also send direct messages and update statuses from a single page.
Note: Seesmic has been acquired by HootSuite.