So you are using a portable browser with an onion router for security. You might even have a privacy proxy set up to strip ad, web page bugs, cookies, etc... But if you are using a public WiFi hotspot, your packets are still available to whoever wants to sniff for them. What can you do?
Tunnel them through SSH of course.
There are several guides out there that tell you how to do this. I'm not going to repeat the instructions. The basic premise is that you forward a particular service, say web over port 80 or SMTP traffic, to an SSH server of your choice, most people set one up at home. Your school or work may have one as well that available for you to use.
By tunneling your web requests over SSH to a web proxy, like Squid, that uses an onion router you can just about ensure that you are the only person that knows what web sites you are browsing.
P.S. You can also use this technique to bypass just about any firewall restrictions.