Skype is a real success story. Unlike social networking sites that are destined to die in a few years time after people get tired of promoting themselves, Skype is actually built on a solid business model and has real end-user benefits. Launched in August 2003, just three years later over 115 million people across the globe were phoning with Skype. The company was bought out by eBay for $2.6 billion in 2005 and currently there are over 310 million user accounts (estimated 35 million active daily users).

You may have heard people say ‘Skype me’ or ‘Are you on Skype?’ and wondered what on earth that’s all about. Skype is a natty software utility that provides a means for you to have voice conversations over the Internet, using VoIP (Voice Over Internet Protocol – a technology that enables voice conversations to be transmitted over a data network using Internet Protocol). There are other companies that offer this service but Skype has become one of the most well-known and well-used – particularly by solo professionals. So what’s the big deal about Skype? Why not just use the good old-fashioned telephone?

Skype – and other VOIP providers – offers free voice calls to other Skype users via your computer: the call is made from your computer and you need microphone and speakers plugged into your computer to use this service. You can also buy telephones that plug into your computer so you can maintain the familiar telephone interface and experience that you’re used to. With Skype you can also make cheap calls to landlines all over the world, using SkypeOut. You pay in some money to your SkypeOut account via your credit card and as you make calls the company takes money out of your kitty and you need to top it up from time to time.

Skype 4.0 for Windows is the most distinctive new release in the company’s relatively short history. The changes have been in development for two years, said Skype, and many of the improvements were based on user feedback. The new version offers full-screen video calling, improved call quality and is easier to use. In addition, you will find all the features you have come to expect – free voice and video calls to other Skype users, instant messaging, SMS, as well as calls to landlines and mobile devices around the world at very low rates.

The classic two-pane interface has consolidated into one, though you can still split them apart if you prefer. The new Conversations Tab makes it easy to keep track of multiple conversations in one place, and you can switch quickly to your preferred communication method – free voice and video calls to other Skype users, instant messaging, SMS, as well as calls to landlines and mobile devices at Skype’s low rates. In addition, you can choose to use Skype in two different views. Default View has everything neatly contained in a single window or Compact View allows you to resize or put each conversation into separate windows.

Video calling is starting to take off, so Skype obviously wants a piece of the action. With Skype 4.0 you can experience the benefits of free face-to-face video calling. It’s now easier to start a video call and experience full-screen video, and a new built-in bandwidth manager ensures that you have the very best Skype video calling experience possible even on a low-bandwidth connection. If you have a fast enough connection (recommended 400Kbps or higher), a dual-core processor PC and a Skype Certified High Quality Video Web camera, Skype can deliver up to 30fps (frames per second).

Regular users of Skype will appreciate improved call quality. The new audio codec, named Silk, achieves wideband audio quality using less bandwidth than previously required. Fewer bandwidth demands gives Skypers with dial-up connections (like a lot of people in India and Africa) a bigger boost, keeping calls from being dropped or mangled beyond recognition. Moreover, it delivers richer and warmer sound to those using a compatible headset and a high quality broadband connection. The bandwidth manager interacts with the codec to adjust quickly to fluctuating bandwidth conditions to produce the most reliable sound.

Those who have been following the triple release of betas since last year won’t see more than a few changes, but the free desktop VoIP communicator is a worthy final version that brings some key enhancements with video and audio bandwidth. In our tests audio quality and video streaming were excellent, although you should remember that quality depends on your Internet connection and hardware configuration. Using headphones that support ultra-wideband audio will also help. You’ll never get the quality of TV, but there were certainly fewer jumps and sound syncing problems compared to previous versions of the software – that’s thanks to the new bandwidth manager that salvages audio first as available bandwidth drops, followed by lowering the rate of frames per second and by compressing images more heavily. Skype 4.0 is a great product that makes VoIP simple and effective. It can downloaded for free at http://www.skype.com/go/download.