Replacing a lost or stolen device is a low cost exercise and re-synchronising the device immediately restores the executive's environment and crucial personal information. However, this should not be seen as an excuse to ignore security issues. The obvious area where problems occur is during file transfer and synchronisation. As for the devices themselves, 32Bit operating systems offer two levels of password protection. The device itself can be locked with a password and individual files within the applications can be locked with another password.
Viruses are always an area of weakness, but the risk on handheld computers is surprisingly small.
In fact, strictly speaking there aren't any viruses that affect handheld devices, only trojans. The majority of these are, however, harmless. Payloads range from switching backlights on and off at irregular intervals to posting insulting messages on the screen. To date, there have been no known cases of trojans that affect the Symbian platform and Palm has only had one seriously damaging case, Liberty Crack, which resulted in total file deletion. Having said this, without going into technical intracacies, there is a script in the latest version of Windows CE V3.0 that has the potential to support virus propagation.