I once submitted a friend's blog entry to slashdot. It was picked for the front page. I can't remember exactly how it works, but you get an email or a notice on the site saying your story will appear shortly.

I was in my friend's living room at the time, sitting near the laptop on the end of an ADSL connection that served his blog.

"Ummmm.... I think i've done a baaaaad thing."

That lil' ol' laptop was absolutely hammered for the next day, even after moving the images, etc., on to 'proper' servers and making the site static.

I submitted my review of of the Unicomp Customizer (http://hardware.slashdot.org/story/08/05/29/1334258/Review-o...) years ago, and I think that day remains the most traffic I've ever gotten. Granted, it's a generic Wordpress.com blog and thus not susceptible to Slashdotting, but I still remember looking at the traffic spike and going, "Wow."