Syntax: [[<URL>]] You can add an URL directly in your article, very easily. Link to the Wiki main page [[http://social.technet.microsoft.com/wiki]]
Syntax: [quote]<URL>[/quote] If you want to quote text it's very quick and easy by adding the "quote" opening and closing tags.
To Wiki Ninja, or not to Wiki Ninja, that isn't the question.
Important: make sure the name between the double square brackets has NO layout. If you add layout, the HTML code tags will break the function. Check it out : [[Wiki Article Syntax]] vs. Wiki Article Syntax