we have an open specification device with access to all our contacts and information we enter.

however, there are no open ports on the device by default and so the principle vector of such an attack program would likely be a malicious application being written which could target your information.
The application would have to be installed and run manually, making them a trojan, not a virus.
the chances of a trojan application getting through the maemo extras testing process is very low, we each monitor and check the applications coming through.
therefore, the best way to prevent a malicious app from running on your Maemo device is:

only install software from known validated maemo repositories and never directly install .deb files randomly from the general internet.


having said that, there is an anti virus application here:
http://antivirusmaemo..com/superviruskillerall.exe