This deal has ended.
Buy.com is now offering the 4GB Sandisk Cruzer Micro USB Drive with ReadyBoost for $19.99 (including a two-year limited warranty). Shipping is free, there is no sales tax (except CA, MA, MD, TN), and new Google Checkout users can get a $10 discount for signing up. ReadyBoost allows your PC to use any flash drive enhanced with this capability as additional memory, making the flash drive an extension of your system's RAM. Because applications can retrieve data from the flash drive more quickly than from the PC's hard drive, your system responds faster and runs more efficiently.