There's a lot to choose from when it comes to buying a flash drive. The most important thing to consider is size. The whole point of a USB drive is to store lots of data in a small space, so think about what kinds of files you'll want to house on your flash drive. Movies and music take quite a bit of space, so if you're carrying your whole entertainment library with you, you'll want a big thumb drive – at least 16GB. Books and other text-based documents require relatively little storage space, so people like students and working professionals using Microsoft Office would be happy transferring Word documents or Excel files with as little as 1GB of space. On the other hand, if you are using photo or music editing software, you'll want a USB flash drive with lots of storage capacity to transfer graphic and music files.
Usually, such drives will be custom-stamped with a company's logo, as a form of advertising. The drive may be blank, or preloaded with graphics, documentation, web links, Flash animation or other multimedia, and free or demonstration software. Some preloaded drives are read-only, while others are configured with both read-only and user-writable segments. Such dual-partition drives are more expensive.[61]
The U3 company works with drive makers (parent company SanDisk as well as others) to deliver custom versions of applications designed for Microsoft Windows from a special flash drive; U3-compatible devices are designed to autoload a menu when plugged into a computer running Windows. Applications must be modified for the U3 platform not to leave any data on the host machine. U3 also provides a software framework for independent software vendors interested in their platform.
USB flash drives usually specify their read and write speeds in megabytes per second (MB/s); read speed is usually faster. These speeds are for optimal conditions; real-world speeds are usually slower. In particular, circumstances that often lead to speeds much lower than advertised are transfer (particularly writing) of many small files rather than a few very large ones, and mixed reading and writing to the same device.
Many types of USB drive, sometimes referred to as a thumb drive, also have handy features like a key chain ring or a small LED flashlight. Some can even transmit your data wirelessly for the ultimate in digital convenience. And as with any fun accessory, there are plenty of novelty versions of flash drives designed to show your personality, display your sense of humor, or broadcast your team loyalty.