Thanks for your reply!
In OSX I added the pccomm.jar-file to the folder Library/Java/Extensions/
I think that's the same as adding it to the classpath (?).
Instead of 7 errors there are 2 errors left:
[color=blue][MacBook-van-Frederik:programming/06_USB_send_receive/USBSend] frederik% javac *.java
USBSend.java:9: unreported exception lejos.pc.comm.NXTCommException; must be caught or declared to be thrown
NXTInfo nxtInfo = nxtComm.search(null, NXTCommFactory.USB);
USBSend.java:16: unreported exception lejos.pc.comm.NXTCommException; must be caught or declared to be thrown
You refered to the comments in USBSend.java, But in my file there are no comments at all. Do we both have different versions of the file?
I'm looking forwards to the tutorial you're writing.