Virtualization: "In computing, virtualization is a broad term that refers to the abstraction of computer resources. - Answers.com"  In layman's terms, this means giving you the services of a computer without necessarily having a computer in front of you.  These tools linked below are communication and productivity tools that do not install on your computer... all you need is an Internet connection and a web browser.  A laptop, a PDA, a PocketPC... yes, an iPhone will all give you access to these virtualized computer applications.