My alligator popup plugin allows a shortcode to be used in WordPress Pages or Posts to enable links to be opened in popup windows. The width and height of the popup can be defined and the popup automatically appears in the centre of the screen.
The plugin was inspired by a question on the WordPress forums. It can be downloaded from the WordPress plugin directory: alligator-popup
[popup url="http://cubecolour.co.uk/wp" height="500" width="460"]Link Text[/popup]
Put in Your Link Text, url, width & height. If no values are given for height and width, defaults of 400px are used.
Here is an Example Link using the shortcode parameters shown above.