Actually HTML has a wonderful way to do spoilers, an example is below. Highlight it if you actually need an explanation of the trick.

Spoiler

The trick is that you write a table with the font and the background color the same. When someone highlight's it they can read the spoiler, but otherwise they cannot. In this case I did it like this: <table><tr><td bgcolor=#000000><font color=#000000> put text here and then </font><td></tr></table> [download] Unfortunately links show through because the rules for the HTML here don't include (that I saw at least) a way to control the color of an HREF. Which is why the link is down there and not in here. :-)

Wish I could claim it was my idea, but one of the folks at IWETHEY (namely CRConrad) came up with it.