Open Opera.
Navigate to the Metacrawler website. (See Resources)
Right-click the search box. A "Search Engine" window will open. Type a name for the search engine in the "Name" text box if you want to change the default name.
Click the check box next to "Use as default search engine" if you want Metacrawler to become your default search engine.
Click the box next to "Use as Speed Dial search engine" to place Metacrawler on your Speed Dial.
Type a keyword in the "Keyword" text box. This will allow you to use Opera's "Address" bar to perform Metacrawler searches. For example, if you want Opera to search Metacrawler when you type the word "xyz" in the address bar, enter "xyz" (without the quotes).
Click "OK."