JJLuna.com supports SSL browsing. If you're on a public WIFI hotspot that didn't require a password to connect, odds are your traffic to all the non-secure sites you visit is completely visible to anyone in range of the wireless access point you are using.
Just like a cordless telephone call can be intercepted, WIFI traffic that is sent via radio waves to your mobile device or computer is just as easy to intercept.
Look for "https://" in front of all addresses that will be using SSL to secure your browser traffic. Nearly all banks and financial web sites will use this feature by default. It's not fool-proof, though it will provide you some level of privacy to others intercepting your browser traffic over Wifi.
When traveling, turn off your WIFI and use the wired connection in your hotel. Better yet bring your own internet to the location - this can be done with a Wifi Hotspot device like Verizon's Mifi cards, Clear's 4G wireless network devices, or even your Smartphone's Personal Hotspot feature if subscribed.