When you’re not interested in waiting for Windows to actually give you the message that it’s okay to eject your USB drive, then take a look here. USB Disk Ejector gives you a nice pretty GUI where you can initiate an ejection by mouse click or keypress. This makes it super easy to take care of USB devices without having to deal with the built-in junk from the operating system.
There’s even a commandline option that allows you to eject things by drive letter, the drive that the program is running from, eject by drive name, or even a partial drive name. Nice. Freeware for Windows.