Smartphones have their own mobile operating system. The first smartphone to find a widespread market was the Blackberry, but that quickly lost ground after Apple introduced the iPhone in 2007. That was followed by smartphones powered by Google’s Android mobile operating system.
Personal Finance: Used mobile phones
Smartphone enthusiasts are keenly waiting for the chance to get their hands on Apple's new iPhone 5. Its launch invites the perennial question of what to do with your old smartphone, which cost so much a year or so ago and was once a must-have item. Is it now a relic?
The easiest option is to take the old item to a mobile phone service provider, such as SmarTone, and trade it in.
The provider will typically give you a credit for the phone, which will then be offset against the cost of your new handset and mobile contract.
SmarTone will give you HK$2,450 of credit for a 16 gigabyte iPhone 4, and HK$3,720 for a Samsung Galaxy S3.
If you take this route, it is worth shopping around, as the trade-in value varies.
If you sign up for a service plan, PCCW will exchange a 16GB iPhone 4 for a credit of HK$2,400, but One2Free offers HK$2,750 for the same iPhone 4 and HK$3,700 for a Samsung Galaxy.
If your old phone is in good condition, you can get better value (and cash upfront) selling to a shop that specialises in used handsets.
The Mobile Phone Direct Selling Centre, which has a shop on Des Voeux Road, is one of several outlets that will pay between HK$3,000 and HK$4,000 for an iPhone 4 or Samsung Galaxy, depending on the condition of the handset.
Another option is to take the handset to one of the phone dealers that operate in small shops in Causeway Bay or Mong Kok. In that case, it helps if your old phone is in mint condition and you still have all the cables and the box it came in.
If you want to try to get the maximum money back for your old handset, it might be worth trying to sell it yourself on the internet.
Websites such as GeoExpat let people post free advertisements on its classifieds pages.
There are currently more than 80 notices from people looking to sell used handsets on the site, with prices for an iPhone 4 ranging from HK$3,000 to HK$5,000. Samsung Galaxies are advertised for about HK$4,500.
But note that this is not the most efficient way to sell. One 32GB iPhone 4S sold for HK$4,200 within 10 days of being listed. Most of the others stay on the site for a long period, with little turnover in listings.
Remember that selling it not only gets you cash, but it may also help others. Many of Hong Kong's used phones are sold to developing countries, such as in Africa, where the cost of a new smartphone would be beyond the budgets of most people.