Twitter’s explosive popularity may have blindsided some business professionals, but others are already firmly entrenched in micro-blogging as a means of engaging stakeholders, increasing their brand visibility and driving traffic to their own Web sites. It’s a smart move, as Twitter is quickly becoming the linchpin of communications, customer service, media relations—you name it, and this Web platform can probably help you do it.

But, with a universe of tweeters that increases exponentially every single day, how do you monitor relevant conversations, manage your brand in the context of these conversations, and then measure the impact your efforts have on achieving your goals? It’s certainly a loaded question but, for every new Twitter user entering the tweet-o-sphere, there seems to be a new, free application to help you manage the inevitable information overload. The following is a list of some of the many, many tools out there at your disposal (the list is always growing and changing, so your recommendations and comments are encouraged):

URL-Shortening Services (+ a bunch of other useful features):

• Bit.ly: Tracks number of users who clicked on your tweeted URL.
• Doiop: Also lets you choose a keyword within the shortened link to provide your followers with context.
• TinyURL: Lets you incorporate a bookmarklet on your browser so you can shorten a URL with a single click without having to go to a different site; also has a preview feature.
• MemURL: Creates mneumonic links that don’t necessarily include a keyword, but at least are easy to pronounce; also has a bookmarklet feature.
• DwarfURL: Tracks statistics and traffic of shortened URLs—great for quantifying click-thrus.
• Cli.gs: Provides stats in real-time; allows you to create custom URLs based on the country of users.
• Zi.ma: Bulk URL shortening service.
• SnipURL: Also has an RSS feed; lets you export your “snips” to Excel.
• POPrl: Shows public stats.
• Twurl: Also organizes URLs for visual searching; tracks the number of clicks your “twurled” URLs get.

Search Services/Monitoring Apps:

• Twitter Search: A mini-search engine built directly into Twitter.
• Tweet Scan: Searches Twitter + other microblogging sites; sends email alerts.
• TwitterTroll: Searches in real-time.
• Twellow: Twitter version of the Yellow Pages.
• Hashtags.org: Keeps track of tweeted hashtags.
• TwitStat: Search tool that also provides analytics and query trends.
• TweetDeck: Software allows users to organize tweets according to @replies, direct messages and keyword searches.
• Twitterholic: Ranks Twitter users by number of followers.
• Twitturly: Tracks the most popular URLs based on how many times they’ve been shared on Twitter.
• Twhirl: Keeps Twitter open on the user’s desktop and updates tweets in real-time.
• Twibs: Provides a list of businesses currently on Twitter, and helps them build followings.
• Twits Like Me: Helps you find Twitter users who share your interests.
• Twitter Feed: Sends your blog/RSS feed directly to Twitter, tweeting updates.

Who-Woulda-Thought-About-That Apps:

• TwitterGram: Lets you send your Flickr pictures to Twitter.
• Twitsay: Allows you to post audio recordings to Twitter.
• TwitterCal: Posts events from your Google calendar directly to Twitter.
• TweetLater: Lets you schedule your tweets to automatically post at a certain time.
• Twibler: Posts eBay listings as tweets.
• TwitPic: Allows users to post a photo and then share the link via Twitter.
• Tipjoy: Lets users send small amounts of money to charities and businesses via Twitter.