chaosclown, firewalls only control what traffic goes in and out. So, firewalls WILL help but you have to remember that ANY traffic that does get through the firewall is then transmitted to everyone in a 100m radius depending on router strength and wall thickness etc etc.
So, everything you post/read on here can be read by anyone else nearby if they so choose. Your online banking should still be safe since its encrypted 128bit anyway by the browser.
Bottom line, anything you can do on this unsecured network anyone else can see you doing with the right hardware/software.
