Have you ever used another computer to find out it doesn’t have a program you really enjoy using? Or, not have it fine tuned to your own style? To avoid situations like these, I always try to carry my pen drive full of Portable Apps.
Portable Apps are programs you can install and run directly from your pen drive, without the need to install anything on the machine itself. The list of applications available is pretty good, including: ClamWin, The Gimp, 7-zip, OpenOffice, VLC, XAMPP, GnuCash, Firefox, Thunderbird, and a couple dozen more.
The nice thing is that you can configure each of these programs to the way you like it. For example, carry your Firefox with the plug-ins you want; have Thunderbird with your email accounts already setup, and Pidgin with all of your accounts already set.
This way I can use someone else’s computer and be able to do almost the same things that I would on mine. To protect my data and passwords, I always keep the Portable Apps directory encrypted.