After several hours, I was able to run Hello World on an NXT using Mac OS 10.6.8. I started with the instructions in the "Intelligence Unleashed" book, but they are either erroneous or out of date in many places. As an aid to others, I summarize here what I had to change.
This went pretty smoothly, but it is vital to start tcsh (step 7 on p. 10). The default shell on OS X is, I think, bash, which won't read the .tcshrc file created in step 5.
The Device Manager screen shot on p. 11 only applies to Windows. I don't know where to find the equivalent info on a Mac, but it's not important.
UPLOADING THE FIRMWARE:
At least from the command line, the Fantom USB driver must first be installed:
http://mindstorms.lego.com/en-us/suppor ... iver.aspx/
Also, there is no hyphen in nxjflashg.
COMPILING AND UPLOADING JAVA CODE
The paths listed here are both Windows-specific and out of date. They should be:
1. cd /Applications/lejos_nxj/samples/src
2. nxjc org/lejos/sample/tune/Tune.java
3. nxj -r org.lejos.sample.tune.Tune
I was only able to get that last line to work AFTER I had gotten it to work via Eclipse, which does the Bluetooth pairing.
CONFIGURING LEJOS IN ECLIPSE
I had to add the leJOS library (NXT, not PC) to the build path for my project and remove the regular JRE from the build path.
CREATING AND UPLOADING A PROGRAM
The program is incorrect. The second line in main() should be:
The quotation marks around "Hello world" should, of course, be straight quotations marks, not the slanted ones printed in the book.
When asked for a bluetooth passcode, I used 1234, which is the default on the NXT. It is possible to change this by digging through the menus on the NXT itself.
With those corrections, I was able to run the program via Bluetooth. I never did get it to work via USB, although I did use USB to flash the firmware.