They are sleek, fashionable and virtually unstoppable. You see them in jewellery, independent 
units, and in watches. We are talking about portable storage devices represented by the ubiquitous MP3 player, USB drive and smart phone. It is predicted that over four-fifths of mobile knowledge workers will have the opportunity to use wireless e-mail by 2008, and smartphones may outnumber PDAs as electronic organisers by the end of 2006….
These devices have led to large productivity gains, especially for companies since employees can work from any place. It is not uncommon to see sales executives equipped with these devices; they can be used for corporate presentations on the move, to record meetings, and to keep memos. They also form a perfect substitute for floppy discs and are far more durable.
However, these conveniences come at a price. Since these devices are portable and can store so much data, they are a prime target for thieves. This situation is particularly grave for corporates since several of these devices are with senior employees who have access to sensitive data. On top of this, several employees bring personal devices and connect them to the corporate network which renders the entire network vulnerable. Demystifying portable device security - Express Computer