I agree with your on wireless networks. There’s just no way to make those 100% safe. Especially if it’s not encrypted. And even then you’re just going with the fact that the odds of someone in your area is not bothering to try and hack your computer.

For public computers, the best you can do is use your own Live-CD OS. Many places do frown upon it, but if they do then I just won’t use them.

As for friends and family, the question is can you really fix it? And in some cases, is it worth it?

For VPN, that’s not safe either. For example if the PC you’re using has a keylogger already installed, it doesn’t matter if you’re using a VPN. All your keystrokes will be logged from the original PC. It’s only an illusion of security. You still need to control the original OS.

The reality is that unless you can control the OS on the PC, it’s not secure. So you can’t really compare with public computers you can’t control. It’s like asking how to make a car safe if you can’t even look at it (to see if it even has gas in the tank). You need some level of control.

Public computers are the main worry as your generally using them when away and only because you need to. ie. banking. A lot of internet cafe’s that I’ve used don’t exactly give you access to be able to run live CDs, or plug in routers. To top that off they’re often time limited and use custom software to restrict this and unless they’re running DHCP it wouldn’t be straight forward to connect to their network.

Friends and families PCs are a little different. You have access to all the settings and can easily configure a live OS although your most likely using their PC to solve thier security issues in the first place.

I think a better/easier alternative is to use an encrypted VPN, If you need even more security then also remote desktop in to another system over the encrypted VPN.