But seriously, just by using the Internet your IP address basically is already public. Your IP address being known isn't that bad or scary. You are far more at risk of being 'hacked' by falling for social engineering tricks, having javascript enabled on all websites and downloading random files. As long as you use common sense, a decent firewall and (when on Windows) a good virus scanner, and keep all your software up-to-date through trustworthy update channels, you should be safe.