I havent personally used Opera, but know a few of you others do.
They have released (yes freeware) Opera 9.1 USB Edition:
PC Authority rating 4/5 starts
Ever wanted to take your favourite web browser on the road, so you can access your preferences, bookmarks and your web history?
Portable versions of programs such as Opera have many advantages. You can be sure of keeping bookmarks and emails accessible no matter what computer is being used.
This portable version of Opera has the added benefit of not leaving any traces of the internet session on the computer. To do this set the Tools - Preferences- Advanced - History - Disk cache option to 0MB.
To get started and to use Opera USB from a USB stick, unzip the ZIP file you download from this site onto a USB key.
All the features of Opera are supported including the email client, IRC chat, notes and contacts.
http://www.pcauthority.com.au/download/ope...sb-edition.aspx
Maybe it old news to some but anyway...