It really annoys me when a site forces you to open a web page in a new window. It really really really really really annoys me when that new window has no toolbar, status bar, bookmarks bar, scroll bars, has been moved, resized or stops you from resizing it.
That is why I've put together an open source safari 5 extension called "WindowControl", that disables web pages from doing this.
WindowControl gives users back the power to control how their browser windows look and behave. New windows will still open, only the child windows will look like their parent windows. No alterations.
You can download the FREE safari extension here.
Update: I've added toggable settings to the extension, so you can choose which parts of your browser window scripts can alter.