10 things you should know about Skype

You've seen the posters, and the words 'free calls' remain etched into the memory as you wonder gripping your current contract-damn handset, whether you should get in on the action.

Before you consider taking the plunge into the world that is Skype, here are 10 things we think you should know about it.

1) How does it work?

Founded by the people that brought you the once file-to-file sharing network marvel that was Kazaa, Skype is a VoIP application easily download-able to your desktop PC or in the case of a Skype-friendly mobile like the iPhone, through the Apple iTunes Store. Using your current internet connection, all you have to do is grab your headset with microphone, hit the green button, and you are ready to call people across the world for free.


2) It's free, well mostly

Chatting to a fellow Skype user whether through your computer or Skype-enabled device will set you back the pricey sum of nothing. But before you dump your contract phone, it will cost you a small fee to talk to someone who is not on Skype. You can own local numbers in a host of countries, with your calls to the number charged at the same rate as calls to fixed lines in your own country. Services like SkypeIn and SkypeOut are the route to contacting people on their existing mobile numbers or land-line numbers. It may sound silly, but ensure you know enough people on Skype to fully embrace the service.


3) Skyping all over the world

Essentially what is great about Skype is being able to talk to your long distant relatives in Oz without the pain of the long-distance charge. That is however not the case for every country. Skype is built on a closed protocol which translated means all equipment used is made by the company but also means that a country like China bans the use of Skype. Having recently refused the allowance of WiFi handsets, over fears users would add internet phone services such as Skype to make calls, unofficially it was claimed that it was because they could not track calls. So if you got mates in China you are hoping to talk to for free you may need to think again.


4) Skype devices

Along with Skype sitting on your toolbar on your PC, mobile network provider 3 provides a series of Skype phone handsets, while the PSP via its Wi-Fi connection can also be used for your free calling. Rumors that Skype could be moving to the DSi have been fierce with the Nintendo calming they did not want to develop a mobile service which required a monthly contract. Also available as an app for the iPhone and iPod Touch, it has proved one of their most popular downloads surpassing more than one million downloads, that's six downloads every second and a clear sign of its popularity.


5) Skype plug-ins

Much like the Apple's App Store, Skype has its own place to add more life to your Skype life and make it more than just a place to chat freely. Built with open developer API, it is a free-for-all for those who want to create plug-ins and a-d ons for Skype and go on sale to other users. So if you fancy a spot of chess with your pal in the Ukraine or chilling out to some tunes on Last.fm, simply head to the Skype Extras store and take a browse.


6) Skype mobiles
If you pick up a one of the Skype mobiles you are essentially getting the best of both worlds. As the users of Skype blossoms into their millions, you can contact them for free while still retaining some of the more familiar mobile phone usability.

Allowing you to make Skype phone calls and use the instant messaging service for free, video calling however is not yet supported. ASUS have recently revealed their EEE Videophone, which is not quite a mobile but fully supports face-to-face calling if you need it. If you don't fancy buying a 3 Skype phone, simply pay up a nominal fee for a 3 sim to use on a compatible unlocked handset, download the application and you are on your way to free call heaven.


7) Video chatting

25% of Skype-to-Skype phone calls include video, and it is one of the features which extend its popularity to the likes of talk show colossal Oprah Winfrey using it on one of her shows. With your web cam connected, hit the green button and then the web cam button and you are on your way to conducting business from overseas, or showing off your latest party trick. It is clearly a great way to cut the cost of paying out for a video conferencing set-up at work and the quality of the feedback is one of the best around.

8) Skype means business

Skype has a genuine presence in the world of business, and it is valued so much by some companies that it has been known to be used to hold job interviews. Solving the dilemma of an overseas candidate having to travel half the side of the globe to be grilled for an hour can be evaded as the video calling via Skype is simplicity in itself, providing slightly grainy but nonetheless a refreshingly clear picture to show off your best job-winning skills to your prospective employee.

9) Skype Messenger

Proof that there is more to Skype than phone calls, the Skype Messenger is also a free service from your PC and from Skype-enabled devices. Considerably one of the most effective and easy to use messengers around, simply build up you contact list and then begin to drag and drop people into your existing chats. Chat history is saved in a way which it is easy to refer back to, while file transferring is a simple drag and drop away from your conversation. Skype also allows you to download videos from sites Daily Motion and Met-cafe so you can chat, watch a video and file share all in the same window.

10) Free forever?

For the time being, yes it is but mobile network providers are all too aware of the growing prominence of the VoIP application and how it may affect their business. With the new roaming regulation in effect since July, some of the major mobile phone manufacturers are wondering whether the service of Skype and your standard mobile phone connection should be paid separately, with Nokia's recent announcement to pre-install their N97 handsets with Skype forcing 02 and Orange to block the sale of the phone through their networks. The likelihood of paying for both services seems unlikely, but not impossible, so while it's still free we suggest you get the most out of this VoIP wonder.

There is no such thing as "deleted" on the Internet!!

It's always fun to write about research that you can actually try out for yourself.

Try this: Take a photo and upload it to Facebook, then after a day or so, note what the URL to the picture is (the actual photo, not the page on which the photo resides), and then delete it. Come back a month later and see if the link works. Chances are: It will.

Facebook isn't alone here. Researchers at Cambridge University (so you know this is legit, people!) have found that nearly half of the social networking sites don't immediately delete pictures when a user requests they be removed. In general, photo-centric websites like Flickr were found to be better at quickly removing deleted photos upon request.

Why do "deleted" photos stick around so long? The problem relates to the way data is stored on large websites: While your personal computer only keeps one copy of a file, large-scale services like Facebook rely on what are called content delivery networks to manage data and distribution. It's a complex system wherein data is copied to multiple intermediate devices, usually to speed up access to files when millions of people are trying to access the service simultaneously. But because changes aren't reflected across the CDN immediately, ghost copies of files tend to linger for days or weeks.

In the case of Facebook, the company says data may hang around until the URL in question is reused, which is usually "after a short period of time." Though obviously that time can vary considerably.

Of course, once a photo escapes from the walled garden of a social network like Facebook, the chances of deleting it permanently fall even further. Google's caching system is remarkably efficient at archiving copies of web content, long after it's removed from the web. Anyone who's ever used Google Image Search can likely tell you a story about clicking on a thumbnail image, only to find that the image has been deleted from the website in question -- yet the thumbnail remains on Google for months. And then there are services like the Wayback Machine, which copy entire websites for posterity, archiving data and pictures forever.

The lesson: Those drunken party photos you don't want people to see? Simply don't upload them to the web, ever, because trying to delete them after you sober up is a tough proposition.