Echofon, HootSuite apps help users keep up with Twitter

Twitter helped spread the Osama bin Laden killing story Sunday night, further cementing the unbounded messaging service as a social force.

Which smartphone applications help most in using it? Here are a few suggestions.

First of all, you can tweet app-free from any mobile phone after signing up for a Twitter account at the Twitter.com website and then sending an initial text message to the site. You'll also need to enlist a follower or two to receive your tweets. Read the FAQ.

Twitter Inc.'s own app - of course, called Twitter - is free for iPhone, iPad, Android, BlackBerry, and Windows Phone 7. With it, you'll easily add photos and location information to your tweets, along with a lot of other features unavailable if you are simply weighing in via text messaging.

Unfortunately, the app won't automatically shorten URLs - the Web links that can chew up precious space if you want to include one in the 140 characters available for a tweet.

On the iPhone, tap the magnifying-glass icon to open a search screen that also shows "trending" subjects - the words or phrases getting a lot of tweets. A "suggested users" function lets you browse for possible tweeters to follow by categories, such as entertainment, books, health, sports, and technology.

Echofon is a free advertising-supported app from Naan Studio that is powerful enough to replace your phone's texting function, if you want it to.

Echofon can be set to notify you of direct Twitter messages, along with notices for all manner of events to boost your vanity index, as when someone decides to follow your tweets or when someone "mentions" you - with an "@" next to your Twitter name - or signals that one of your tweets is a "favorite."

A "mute" button allows you to turn off, or squelch, unwanted users, keywords, and even other apps that people use to post to Twitter. And if you want to tweet a Web page, the application will automatically shorten the URL.

HootSuite for Twitter, by HootSuite Media Inc., is free for Apple, Android, and BlackBerry. This app is billed as a "social-media dashboard." That's because HootSuite can be configured to stay in touch with your Facebook, LinkedIn, and Foursquare accounts along with Twitter.

One thing you might notice over time on Twitter is a large number of foreign-language tweets. That's why you may like HootSuite, which has a translation function good for translating back and forth in 50 languages. It's just a click away from any text.