How to boot from a USB drive in VirtualBox (open source virtualisation software) ?

1. Download Plop Boot Manager
2. Extract the file plpbt.iso from the ZIP archive and save it somewhere.
3. Open the settings for the virtual machine and attach the ISO file:

   

4. Add a filter for the USB device:

   

5. Boot the VM and select the “USB” option in the menu:

   

If all went well, the machine should now boot from the USB device.