Have you upgraded to Firefox 4? Not yet? Mozilla released Firefox 4 final yesterday with a streamlined user interface, speed, tab grouping feature (Panorama). If you’re looking for Firefox 4 final portable, the good news is that PortableApps site has released it.
With this portable version, you can able to browse and surf the web same way as installable Firefox version. You can install themes, extensions and carry all your settings, bookmarks, extensions on the go with you in your USB Flash drive.
Related: Download Firefox 5 Final Portable
No data will be saved to the Computer you’re surfing from.