Carry your favourite software in your pendrive and use them without any installation in any computer is not a dream any more. There are three advantages to use portable software. First, convenient, you can carry your favorite computer programs along with all of your favorite bookmarks, settings, email and more on any Windows computer without leaving any personal data behind. I believe it is very helpful for student like who are using public computer daily in University.
Next, Portable Applications are open source. In other words, they provides a truly open platform that works with any hardware you like (USB flash drive, iPod, portable hard drive, etc). The entire platform is open source built around an open format that any hardware or software provider can use. I love open source so much, it is more secure since its source code is always available for you to take a look, partial or full source code. It provides an opportunity for programmer to learn and develop, as well as to ensure there is no so-called "back door" in the software.
Lastly, The Portable Applications Suite and Platform is free. It contains no spyware. There are no advertisements. It isn't a limited or trial version. There is no additional hardware or software to buy. You don't even have to give out your email address. It's 100% free to use, free to copy and free to share.
As a way to appreciate the experts behind and their contribution, try it now at http://portableapps.com/. The figure below illustrates my what I call my mobile computer which consists of all my favorite software such as Open Office, Google Chrome, PDF viewer, calculator, antivirus, anti spyware and so on. Enjoy those fantastic software now^^