The flash drive, commonly called a USB memory key, is well on its way to becoming the floppy disk of the new millennium. Since virtually every desktop computer manufactured in the last five years has a USB port, flash drives provide a convenient method for transferring data between systems. Just plug one into your PC, and it shows up on your desktop as another storage device. Recently, we've started to see manufacturers differentiate their products by adding more security and fun features.

Declining prices and increasing capacities make flash drives a compelling purchase. We found 128MB flash drives online for around $60, but sales and bargains can drop prices to as low as $30. Although 16MB, 32MB, and even 64MB flash drives are very inexpensive (if you can still find them), they are too small to be useful for transporting large graphics and PowerPoint presentations. Keys with 128MB and 256MB capacities are the most popular and cost-effective models on the market. Models up to 2GB are available, but prices increase disproportionately.

Flash drives with USB 2.0 interfaces also cost more. But if your computer supports that standard, you'd be much better off buying a USB 2.0 device because of the vastly increased speed.