So the world appears completely besotted with Twitter, the Web service that lets users send short, 140-character messages, called tweets, to followers. Users can also follow friends, favorite Web sites, famous people – even personal finance blogs (such as the Wallet).

Banks, retailers and other large companies have also signed on to the service, and savvy Twitter users are finding ways to save money and get responses to consumer complaints. Here’s a brief rundown:

Following your favorite retailers or deal sites on Twitter can alert you to limited-time or exclusive sales. Airlines, including Southwest and jetBlue, have a strong presence on Twitter, where they point followers to fare sales or passenger trends. For electronics fiends, Amazon and Dell have both offered special deals to their Twitter followers.

Even better than discounts for people weary of automated customer-service lines, Twitter is rapidly becoming a place where consumers can share complaints and receive personal responses form companies.

Dell, which has long required its customer service representatives to monitor blogs and respond to bad press. Dell now sifts through tweets, as do customer service representatives from UPS, Comcast and Bank of America. Someone even contacted Bank of America through Twitter and got a fee waived.

“Our customers were out there,” says Holly Hastings, national customer experience executive for Bank of America. “We had to start responding to our customers on Twitter.”

David Knapp oversees Bank of America’s Twitter account, searching tweets that mention the company and contacting users to offer help. Twitter users can directly message Knapp, who then refers the customer to a phone number or appropriate channel.

Hastings estimates more than 300 customers have resolved issues through Twitter since the bank signed on in early January, and Knapp’s Twitter feed has over 1,200 followers. BoA may expand the program in the future to meet customer demand, but, says Ms. Hastings, wants to “keep it personalized.”

Twitter can also keep you on top of financial news. Most news outlets and blogs have twitter feeds that will churn out a headline and URL to a story in 140 characters or less. (You can follow The Wallet, The Wall Street Journal’s personal finance and investing blog at twitter.com/WSJWallet.)

There are budgeting benefits, too. With the added download TweetWhatYouSpend for Twitter, you can import your expenses on Twitter from your mobile phone, establish spending limits, categorize your spending and download that information as a spreadsheet. We particularly like this for tracking business expense accounts.

The added layer of “do I really need this” questioning that comes with knowing that you must commit purchases to Twitter is another added benefit. You can add privacy settings so that only people you approve as followers can track your spending patterns, or keep the feed public and see what role shame has.

If you have a Twitter account and the urge to follow stocks and buzz in the investing community, join StockTwits. StockTwits is a social networking tool for investors. You can hear what people are trading and why, or follow specific ticker symbols for companies you’re interested in. It’s also a great medium for those short outbursts that the market may induce.

Then again, if you prefer to not have minute-by-minute updates on your portfolio these days, it’s completely understandable.