There are so many Portable version of Browsers are available on the net, which you can use from your USB. But Xenocode is an new Postable app which help you to run applications including Safari, Internet Explorer, and other desktop and web-based apps like Google Talk, Gimp, and Adobe Reader. Unlike traditional software applications, Xenocode WebApps do not require any software to be installed and allow multiple application versions to run side-by-side on any version of Windows.
Xenocode requires no setup, configuration, clients, or device drivers, insulates applications against conflicts, and runs existing applications seamlessly on Windows Vista and locked-down desktops.
Good, I love the portable apps