It seems that they started taking hold of the Internet a week ago, and if not for the fact that the holiday has passed, they'd probably still be with us. What am I talking about?
The most prominent one on the web would have to be the one at xkcd, if only because he's got the largest following.
But over at the blog 360, there was a post on the same day showing you how to make your own pop-up Sierpinski Valentine card. As a bonus, there are photos taken with a dinosaur (a T-rex, not a raptor).
And then there's Extreme Cards and Papercrafting, which had a fractal pop-up valentine card and mentions Sierpinski's Triangle in the same post. (On top of that, it was posted a week earlier than the other two.)
Does three instances constitute a meme? It's hard to tell. A web search shows thousands of hits, but most are copies of the xkcd cartoon (did I mention Randall's popularity on the web?).
However, I was also able to track down one more. This was is a Java applet that draws the valentine while you watch: ColorAura Networks posted this with a copyright date of 2003. Well, if that started it, it was slow in spreading.
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