What format will you save in when you write something down?

Plain txt

text in **bold**, a [link](http://google.com) ![image](http://is.gd/MYl7Fu) void helloWorld() { System.out.printf("Hello, world!"); }

text in bold, a link

void helloWorld() {
    System.out.printf("Hello, world!");
}

Jekyll / Octopress

Lots of HTML5 presentation tools support Markdown:

Hekyll, SlideDown, ShowOff, Himpress, KeyDown