I use USB ports, cables, and plugs more for charging stuff since I rarely need to copy files from one computer or device to another because I just mainly use one computer, and I don't really use MP3 and video players, or other stuff which can be used to copy and paste files by using USB.
Although, my printer uses USB, so I sometimes use it to scan and print documents and photos a few times a year.
I would say personally I use it more for charging stuff than copying files. The only time I tend to copy files or even folders over with a USB stick is when I am formatting my laptop.
Same for me, I tend to copy files when I get a new computer, or need to reinstall my operating system, but these days I just use 2 drives to seperate my operating system and programs by putting my personal files on another drive installed on my desktop PC.
I notice more portable devices like Tablets, Smartphones, MP3 Players, and some gaming handhelds mostly use the USB port/plug to charge even when using the wall power chargers to charge. I'm seeing fewer devices which has a seperate power port, and USB port.
I only use USB for downloading photos from my phone and flashing roms. I have a phone dock for charging the phone and my car charges my iPod, so I never need to use the USB ports for charging any more.
