Finding elements inside of iFrames 26/07/2012
# Finding the frame first
frame = browser.frame(:id => '<iframe_id>') 

# Finding a link inside of the frame
element = frame.link(:id => '<link_id>')

When accessing page elements in iframes, one needs to use the reference to the frame and then find elements inside of it with the usual watir-webdriver syntax. The element inside of the frame could be anything but a link is used in this example.