Or just shutdown the computer and it will safely shut the device down.
A word of warning.
I had an external USB notebook drive, made available from a HD upgrade, and lost the safely remove hardware thing. I waited for like a minute that was like after 5 minutes of looking for the safely remove hardware button.
I did the yank.
After that the HD did not work.
It made noise and the light flashed.
I even put it in my notebook to see if that would get it going, nada.
I then said, lets take it apart since its a piece of garbage as is.
It seems the disc head was stuck on the platter. It was real tight. I could not get it off as I know they are delicate. I plugged it in via USB again and I could see it tried to spin. I finally used a screw driver to help spin the platter. After several tries I was able to get the platter spinning and the head got off it (dam magnet on that little head is like way strong).
I put the HD back together and it seemed to work for maybe a couple of months but eventually got to many errors and died. You see you are not suppose to take a hard drive apart like that and open it in a nonclean room. Also the spinning start, on one attempt the screwdriver jumped off and contacted the platter.
At least for external Toshiba drives be careful since thats what mine was, and another person told me the same story about a Toshiba drive he yanked. After telling him my story he took his apart and found a similar stuck head to platter. He says he got his going with no ill affects though and allegedly its still working. This was the story as told to me so maybe fact or maybe bullshit water cooler talk at work since opening up a hard drive is like the last thing to do as even dust ruins them and I think they are sealed under inert gas or something as well.
Other than the HD head/platter issue the worse I think you can do with a yank is corrupting the memory in the device (flash drive, hard drive, etc) and though you may loose data I believe the device is recoverable with a Format.
I have heard/read from some that it can hurt your HD on your computer as well by yanking during writing but I have never seen this in official literature and think thats urban legend from being confused with the facts of possible corrupting the USB device that is being written to if yanked.
None the less this is still like a one in a hundred or thousand thing so even with a yank you are safe almost all the time.
IF ANYONE KNOWS HOW TO GET THE REMOVE USB DEVICE SAFELY IF NOT READILY AVAILABLE, then I too would be interested in the instructions on how to bring it up manually.