Open the Google Maps website in Opera.
Right-click in the search box at the top of the Google Maps page and click "Create Search."
Click the "Details" button in the Search Engine window that appears to view the Address box.
Copy and paste "http://maps.google.com/maps?q=%s" into the "Address" box on the Create Search window, replacing the automatically generated address.
Type a keyword such as "gm" into the "Keyword" box. You can use this keyword to search Google Maps from the address bar. For example, type "gm restaurant" into the Opera address bar and press "Enter" to search for nearby restaurants.
Click "OK."