The Online Family answers:

Most security risks come up for mobile phones when you're using your phone like a computer -- to send email, store information or to browse the web. And if you're using your personal mobile phone to send work-related text messages, for example, you should definitely be concerned. Those messages could be intercepted by hackers or exploited if you lose your phone. The text messages you're sending via your mobile phone do not go through a company's email server so they aren't as secure. Also, wireless handheld devices like phones can receive viruses if you're using them to access instant messaging programs. In general, don't store sensitive information on your phone -- like not putting a credit card number in your phone's "memo pad" -- and be aware of the risks before using it to access the Net.