The Memory Size Visualiser shows the size of common measurements and storage devices relative to each other. Each size is represented by the width/height of the square.
You can zoom in and out by using the scroll wheel or the up and down keys on the keyboard. You can also use Home and End to skip to the smallest and largest measurements.
decimal.js by Michael Mclaughlin.
Mouse image taken from Wikimedia Commons, originally from the Tango Desktop Project.
Floppy disk image by King of Hearts on Wikimedia Commons; edited by OokiePigster.