I mentioned in
this thread that I was able surf the Internet on my Zaurus using a bluetooth connection to my Mac. But somewhere along the line it stopped working (perhaps when I upgraded to Tiger). I could connect to the Mac and use things like FTP, but not surf the net. This thread made me realize that I had to open some ports in the firewall to get it to work again. I opened up ports 80 and 443 (for secure web sites) and now I am surfing with no problems.
(See the thread above if you want the bluetooth sharing scripts I used.)
Edit: After trying to enable this on another machine, I discovered that the port settings weren't really my problem, although they are helpful when setting up the firewall. By coincidence, the machine on which I was able to get this to work had Internet sharing (to its ethernet port from airport) enabled. It turns out that unless I have Internet sharing enabled, I can't use the Internet through the Zaurus, even though I have it set to an unrelated port. It's not a big deal to enable this, since I don't use the ethernet port anyway, but I was wondering if there was another way to do this.