Windows ReadyBoost, a new technology employed by the Vista operating system, allows you to use removable flash memory such as a USB drive to augment the computer's RAM and boost performance. You can even specify how much space should be allocated from the flash memory. In order to be used for this purpose, a USB device must be between 256MB and 4GB, with at least 64MB of free space, and must support USB 2.0.

Note, as soon as the flash drive is removed, system performance returns to its usual level.