By default, Safari 5 will open links with a target _blank attribute in a new Safari window.

I don’t like this as I prefer to browse in one window. Many of you might have the preference of opening links in a new instead of a new window.

To do this, go to Safari > Preferences (or press Cmd + ,) and then go to the “Tabs” section and change the “Open pages in tabs instead of windows” to “Always” like this: