Security of WiFi networks

Generally speaking, there are lots of wifi [wireless fidelity] networks popping up all over and they're great to use because they are so fast and so easy to log onto [if free]. The problem is that others are doing it as well and once Joe, Susan, Tom, Sally, Jane and George log on and you do too, if your computer is open, you are all networked and any one of you [or others] can jump onto your machine and take or leave things that you'd rather them not taking or leaving [such as private information or malware].

First rule of thumb is to turn filesharing off of your computer if you're accessing an open wifi network. A friend of mine recently wrote:

BTW, recently, when I was in a hotel, I could see about a dozen computers in
my Finder. Some were completely open and files could be accessed by anyone.
Leopard automatically connects to open systems. Curiosity made me look but I
didn't stay.

My advice: when traveling, keep your file sharing off.

The article which started this ruminating is at the JiWire website, the blog comment [newsletter] for 12/14 [Ask JiWire]