claudio@claudio-P5PL2-E:~$ lsusb && lsusb -t 
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 192f:0416 Avago Technologies, Pte. ADNS-5700 Optical Mouse Controller (3-button)
Bus 003 Device 052: ID 18a5:0237 Verbatim, Ltd Portable Harddrive (500 GB)
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
    |__ Port 1: Dev 52, If 0, Class=Mass Storage, Driver=usb-storage, 12M
    |__ Port 2: Dev 2, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
claudio@claudio-P5PL2-E:~$