First, it's important to realize that even if you're on an open public wi-fi network, your website data, logins, and accounts are protected if you are accessing sites which use SSL encryption (sites that start with https:// and show a lock icon in your browser). Most every financial website does this by default, and now most Google sites you log into (like Gmail) do this by default. However, some sites use SSL only for the login process, then drop back to unencrypted connections after login; such sites are still vulnerable to someone stealing your account info via the Firesheep method.Bottom line - if you are logged-into your account on any site, and the site address shows http:// at the beginning, your account is vulnerable to being attacked on a publlic network.There are add-ins you can install in your web browser (such as Force-TLS for Firefox) that will attempt to use secure SSL (https://) connections for all sites which support it, even if those sites normally don't use SSL by default. However, currently not every site supports SSL.Also, if you use a native email client (like Outlook, Thunderbird, or OS X Mail) you need to make sure that it's configured to connect to your incoming and outgoing mail servers using a secure encrypted connections, which are safe even on a public network. Many mail servers offer insecure as well as secure connections, so be sure you're using the secure ones. This can be a little tricky depending on your email provider and client you're using – you may need to check with your provider for instructions. See Securing email on Thunderbird, OS X Mail, and Gmail for a starting point.The most comprehensive solution is to use some form of VPN, as Aaron mentions. I don't have much experience with VPNs, but here's a VPN article from Mashable to get you started. Some of these are paid solutions, but the upside is easy setup for non-geeks.Since a lot of geeks probably read this blog, you can make your own VPN-on-the-cheap if you have ssh (secure shell) access to a remote server. You'll create what's called a 'secure tunnel' over ssh. Basically this creates a secure connection between your computer and your remote server, then funnels whatever traffic you want (web, email, IM, etc) though the tunnel. Paul Stamatiou shows how to do this to secure your web browsing on Mac OS X. Engadget explains tunnels and shows how to protect your email. These articles are Mac-centric, but you can make an SSH tunnel on any platform (even Windows, using PuTTY) – teh Google is your friend here.Finally, if you're using your iPhone, iPad, Android, netbook, PSP or whatever on an open public wi-fi network, you're just as exposed to these threats as you would be on a laptop, although the solutions may not be as straightforward.I knew about these threats years ago, and knew I should make sure I was secure when on public networks. I just got lazy and never did it. Now that Firesheep is out there, any bozo with Firefox at a coffeeshop can easily hijack your Facebook account or worse. It's time to get serious about security, and Eric Butler did us all a favor by making Firesheep available – it forces the issue.