If you don't want to install Opera in your system but still want to try it, you can download the portable version and can directly run it without any installation.
You can also store it in your USB thumb drive and can carry it with you to use it anywhere you want.
Download Opera Portable Version
Posted by: Vishal Gupta | Categories: Opera
Bhavesh
With new Opera installer, Opera can be installed in a portable folder with commandline switches. No need for Portableapps version. Also Portableapps don't have 64 bit version.
my.opera.com/desktopteam/blog/2010/10/22/the-new-opera-installer