I've created a useful little shell script that simplifies managing the default or current JVM that is used from the command line and other utilities under Mac OS X. Most people that run multiple JVMs for development and testing know that you can switch the symbolic link used by the Java JVM Framework to point to the current JVM.
My little script, setjvm.sh, automates manipulating this link and reports on the status of the link so you know where it is pointing. Download it and give it a try. It might be overly complicated, but it beats writing the symbolic link by hand.
[robg adds: I've created a local mirror of the script. Note that I haven't tested this one.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20051205180348164