To use Google Instant, you need Firefox, Chrome, Safari or IE...!!! So, if you want it to work with Opera, you have to make Google think that you're using one of these browsers. Luckily, Opera has weird advanced features built into it. It can appear to be another browser to any particular website.
- Go to http://www.google.com
- Right-click anywhere on the page and select 'Edit site preferences...'
- In the dialog box that appears, switch to the Network tab.
- Here, find the dropdown menu at the bottom and change it to the option shown here: