USB On-The-GO (USB OTG) is a cool, relatively unknown feature on mobile devices that enables us to connect and access normal USB flash drive or storage without the need of ordinary PC. You can view, copy, cut, paste and delete contents on the USB flash drive right from mobile devices. For example you can connect ordinary USB keyboard, digital cameras or USB hard disk to your mobile using USB OTG if it supports.
In 2001 USB OTG was thought of as part of supplement to the USB 2.0 specification, but did not pickup and is available on few mobile devices of Nokia, BenQ and some other brands.
Checkout USB On-The-Go in action with Nokia N8, USB flash drive and Nokia C5 in below video.