Ask HN: What is something you would recommend learning in a day?
I want to pick up a new skill in a day or two. Whether it be a new programming language, API, or something completely unrelated to technology, I'm open to ideas. What do you suggest?
http://www.ehow.com/how_4563591_origami-bookmark.html
However, don't go overboard with the paper :-)
Or how to fix something: a leaky faucet or toilet.
I also second the recommendation to ballroom dance.