How can I use/emulate Selenium RC with WebDriver?

The Java version of WebDriver provides an implementation of the Selenium-RC API. It allows those who have existing test suites using the Selenium-RC API to use WebDriver under the covers.

Example:

// You may use any WebDriver implementation. Firefox is used here as an example
WebDriver driver = new FirefoxDriver();

// A "base url", used by selenium to resolve relative URLs
 String baseUrl = "http://www.google.com";

// Create the Selenium implementation
Selenium selenium = new WebDriverBackedSelenium(driver, baseUrl);

// Perform actions with selenium
selenium.open("http://www.google.com");
selenium.type("name=q", "cheese");
selenium.click("name=btnG");

// Get the underlying WebDriver implementation back. This will refer to the
// same WebDriver instance as the "driver" variable above.
WebDriver driverInstance = ((WebDriverBackedSelenium) selenium).getWrappedDriver();

//Finally, close the browser. Call stop on the WebDriverBackedSelenium instance
//instead of calling driver.quit(). Otherwise, the JVM will continue running after
//the browser has been closed.
selenium.stop();