Imagine you write in a non-Latin based script and you are stuck in a foreign airport internet kiosk trying to figure out how to email in your language. Probably the PC you are using has a different set of keyboard other than qwerty and their is no multilingual support in the OS. There are some online tools which can come to your rescue.
A virtual keyboard is a software component that allows a user to enter characters. A virtual keyboard can usually be operated with multiple input devices, which may include a touchscreen, an actual keyboard and a computer mouse. (Wikipedia )
Virtual keyboards are commonly used as an on-screen input method in devices with no physical keyboard, such as a pocket computer, personal digital assistant (PDA), tablet computer or touchscreen equipped mobile phone. There are many forms of web-based virtual keyboards. One such great online tool is Gate2Home Virtual Keyboard .
“This site enables you to write in your language wherever you are in the world, with an online onscreen keyboard emulator.
The main purpose of this site is to let everyone who gets stuck without the ability to write/type/search the internet in their own language be able to do just that (usually travelers/tourists or anyone in front of a foreign computer).”
The main feature is that you can choose from a list of keyboard layouts your base keyboard of the pc and select the keyboard of your own language (which maps perfectly) and can use the pc keyboard as well as mouse to enter the words.
The site and the gadget got “honorable mention” in Google Desktop Gadgets Contest  and was a main gadget in iGoogle for a long time.
Another such virtual keyboard is Branah.com  which supports 53 languages.
Transliteration is a form of translation, and is the practice of converting a text from one script into another. (Wikipedia )
Systematic transliteration is a mapping from one system of writing into another, word by word, or ideally letter by letter. Google Transliteration  is one such widely used tool. New Melchizedec Sundararaj, Software Engineer at Google wrote  in April 2010:
For many Internet users, it is not always easy to write in languages that use unique character sets like Hindi, Hebrew and Arabic. Most computer keyboards only allow for the input of Roman characters (the alphabet used by most Western languages) and converting between scripts can be difficult. To make this process easier we launched an improved version of Google Transliteration at the end of last year, a service which enables you to phonetically convert Roman letters into a variety of other scripts.
It is important to enable users to create online contents in their own language as no communication can be meaningful and oriented in absence of proper language. Virtual Keyboards & Transliteration tools helps us overcome the language barrier online.