Full disclosure here: I have absolutely no working knowledge of Ruby.
However, I’m pretty good with Selenium so I think I can help. I think what you’re looking for is the select method. If ruby is anything like the other drivers you can use the select method to tell one of the options it is selected.
In pseudocode/java terms it would look something like this
WebElement select = driver.findElement(By.name("select"));
List<WebElement> options = select.findElements(By.tagName("option"));
for(WebElement option : options){
if(option.getText().equals("Name you want")) {
option.click();
break;
}
}
The Select object you have above is actually in a special Support package. It only exists for Java and .Net at the moment (Jan 2011)