To help visualize the difference between kilobytes, megabytes and other bytes the people at IBM Systems Magazine decided to find out how much "weight" our storage tools could hold if bytes were grams.
A 25 MB Gmail attachment, for instance, would have a mass equal to 1.3 International Space Stations. That terabyte harddrive you may have lounging around in your room would be equal to five Sears Towers. That 16 GB flash drive you use? It could hold the mass of Japanese World War II cruiser Chokai.
So the next time you see your cat, remember that 10 of them would be able to fit into a floppy disk. [IBM Systems Magazine]