Yes, Integral USB 3.0 Flash Drives and card readers are backwards compatible with USB 2.0 and USB 1.1 ports. The USB 3.0 Flash Drive or card reader will work at the speed of the port, for example if you use a USB 3.0 Flash Drive in your USB 2.0 laptop it will work at the USB 2.0 speed.
To use USB 3.0 ports you will need a driver from the manufacturer of your PC, motherboard or PCI card. The standard USB Mass Storage Driver from Microsoft (included in Windows XP/Vista and 7 will work - but may not provide optimal performance.
In didn't know that its compatible with even with 1.1 ports as well. Thanks for the information.