Web pages that helpfully open a new window when I click a link were quickly on their way to becoming my latest pet peeve (if I want a new window, I'll hold down the shift key). Opening new windows is a horrible way to keep users from leaving your site. Digg is one of many offenders. That is until I discovered that Firefox can force the links to open up in the same tab/window. You'll find the setting in the "Tabs" tab in the Firefox preferences.