WordPress.org

Author: Andy "Weasel" Moore

Hides text behind a black text/black background tile. Holding the mouse over the text reveals it. Insipred by Something Awful's spoiler system.

Usage: Simply put a [SPOILER]tag around your text[/SPOILER] that you wish to become "spoilered." Works in both comments and posts.

See a sample of it in use here.