How do you keep your stuff private on WiFi networks?

I was talking with a geek who’ll remain unnamed and he was telling me how easy it is for someone to sit at a Starbucks, slurp off the local WiFi, and recreate almost everything you do, often gaining passwords and private conversations. I saw this once at a conference where someone up on stage was showing the audience everything that was going over the WiFi networks. For instance, did you know that if you’re using many common Instant Messengers that those send your information over WiFi in plain text? I could be sitting next to you watching EVERYTHING you are typing across the Internet.

So, what do you do to keep your stuff confidential? Any tips beyond this excellent article in Security Focus on this topic? By the way, both this article and my geek friend recommended Off-the-Record Messenging if you want to hold private IM conversations over public WiFi networks.

UPDATE: I had a post here about Browzar, but there are some concerns about it so I pulled that part of the post to protect people.