Nowadays in the world people daily buy thousands mobile phones. Usually nobody reads manuals so very often people do not know about whole potential of their brand new phones. Most people know that using a phone they can make calls, send messages, shoot pictures with built-in camera and go online. Much less people know that they also can install extra software such as games, applications along with themes. Themes are what I would tell you about in this article.

Mobile phone theme is a special file which includes a set of pictures, icons and sometimes ringtones. Themes are used to decorate and personalize your phone, change fonts size and colors to make texts and labels more readable and convenient.

Themes for Nokia phones are files with .sis or .nth extension. Sis files are used for phones based on S60 platform (which includes such phones as Nokia 6600, 6630, 3250, N76 and other). Nth files are used for phones based on S40 platform (such as Nokia 6230i, 6300, 6125 and so on).

There are a lot of websites where you can buy quite different themes, but also there are some websites where quality themes are downloadable for free, like OnSmartPhone.com. You can select your phone and desired category and download themes absolutely free, without registration or whatever.

After that you need to transfer theme file to your phone. You can do this over Bluetooth or infrared port or copy the file onto your phone's memory card with a USB card reader. When a theme is transferred into your phone you can install it as software if using S60 phone or simply select it from gallery and apply on S40.

At OnSmartPhone.com you can also download themes for other phones like Sony Ericsson and Motorola but they will be discussed in other articles.

Andrew Sekachev is the editor and content manager of http://www.onsmartphone.com/ and http://www.60series.com/ .