Today's mobile devices are beginning to gain computing power and are becoming cheaper, thus allowing more people to buy them. That's why I assume that in the next five years we can expect many attacks against phones and PDAs. People wear mobile devices with them wherever they go (I do, anyway); they connect to the Net whenever they have the opportunity; they read email and browse the web. It's an ideal milieu for worms, computer viruses, and Trojan horses. I hope I've contributed at least a little (and in the future will contribute more) to improving the state of mobile device security.