Under OSX, following the rules you stated (open source and/or legal software that comes with a license): * ClamXav - antivirus * Littlesnitch * Spa

Under OSX, following the rules you stated (open source and/or legal software that comes with a license): * ClamXav - antivirus * Littlesnitch * SpamSieve (Mail App spam filter) * Use local installation on Unbound on foreign WiFi networks Enable the default firewall is a good call also :-). I'd say enable 'encryption' but, IMHO it's better to have a something like Prey running if you laptop costs more than the data within. Otherwise, sure go with encryption.