If you get this error when launching Arduino:
Uncaught exception in main method: java.lang.UnsatisfiedLinkError: Native Library /Users/anu/Desktop/arduino-0002/librxtxSerial.jnilib already loaded in another classloader
you probably have an old version of the communications library lying around. Search for
/System/Library/Frameworks/JavaVM.framework/ or in directories in your
PATH environment variables.