Some manufacturers, aiming at a "best of both worlds" solution, have produced card readers that approach the size and form of USB flash drives (e.g., Kingston MobileLite,[65] SanDisk MobileMate[66]) These readers are limited to a specific subset of memory card formats (such as SD, microSD, or Memory Stick), and often completely enclose the card, offering durability and portability approaching, if not quite equal to, that of a flash drive. Although the combined cost of a mini-reader and a memory card is usually slightly higher than a USB flash drive of comparable capacity, the reader + card solution offers additional flexibility of use, and virtually "unlimited" capacity. The ubiquity of SD cards is such that, circa 2011, due to economies of scale, their price is now less than an equivalent-capacity USB flash drive, even with the added cost of a USB SD card reader.
Flash memory combines a number of older technologies, with lower cost, lower power consumption and small size made possible by advances in microprocessor technology. The memory storage was based on earlier EPROM and EEPROM technologies. These had limited capacity, were slow for both reading and writing, required complex high-voltage drive circuitry, and could be re-written only after erasing the entire contents of the chip.
In the arcade game In the Groove and more commonly In The Groove 2, flash drives are used to transfer high scores, screenshots, dance edits, and combos throughout sessions. As of software revision 21 (R21), players can also store custom songs and play them on any machine on which this feature is enabled. While use of flash drives is common, the drive must be Linux compatible.
Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second (MB/s), megabits per second (Mbit/s), or in optical drive multipliers such as "180X" (180 times 150 KiB/s).[19] File transfer rates vary considerably among devices. Second generation flash drives have claimed to read at up to 30 MB/s and write at about half that rate, which was about 20 times faster than the theoretical transfer rate achievable by the previous model, USB 1.1, which is limited to 12 Mbit/s (1.5 MB/s) with accounted overhead.[20] The effective transfer rate of a device is significantly affected by the data access pattern.[21]
Unlike solid-state memory, hard drives are susceptible to damage by shock (e.g., a short fall) and vibration, have limitations on use at high altitude, and although they are shielded by their casings, they are vulnerable when exposed to strong magnetic fields. In terms of overall mass, hard drives are usually larger and heavier than flash drives; however, hard disks sometimes weigh less per unit of storage. Like flash drives, hard disks also suffer from file fragmentation, which can reduce access speed.
You can get USB 3.0 speed in a compact and durable metal USB drive from Kingston for under $10. It sports a capless design with a sturdy keyring, perfect for travel or as a part of your everyday carry. The design can even be customized to add your logo or company name. Read speeds top 100 Mb/s, while write speeds are on the slow end. With a five-year warranty, a great design, and a value price, this small drive makes a perfect addition to your keyring. 
_{Inside the plastic casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs).[citation needed] Typically, one of these ICs provides an interface between the USB connector and the onboard memory, while the other is the flash memory. Drives typically use the USB mass storage device class to communicate with the host.[28]}

Inside the plastic casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs).[citation needed] Typically, one of these ICs provides an interface between the USB connector and the onboard memory, while the other is the flash memory. Drives typically use the USB mass storage device class to communicate with the host.[28]

^{The entire case of the Kingston flash drive slides into the USB port, making it a tremendously compact and sleek option for data storage. The hole in the back allows it to be attached to a keychain, which ensures you won’t forget it at home when you need it at work. Pros: Affordable, sleek design, good option for travel. Cons: Some found that the small casing made it more delicate Image Courtesy of Amazon}
Flash drives are also cost-effective. You can securely store a few dozen gigabytes of data for less than $30, and these devices range in storage capacity, price and overall size - equal to the amount you're willing to invest. Some even have special features like lanyards, locks, belt clips and key fobs to make them easier to carry and keep track of.
The entire case of the Kingston flash drive slides into the USB port, making it a tremendously compact and sleek option for data storage. The hole in the back allows it to be attached to a keychain, which ensures you won’t forget it at home when you need it at work. Pros: Affordable, sleek design, good option for travel. Cons: Some found that the small casing made it more delicate Image Courtesy of Amazon
^{In addition to providing reliable storage for information, many of these products come with security software that protects your personal data if you lose your device. The software secures files with 128-bit AES encryption and requires a password to unlock the stored information. It also features a drag-and-drop user interface that simplifies transferring and securing your data.}