"You could fake this by creating an account Jail with the minimum of rights and then running Safari with
su Jail -c /Applications/Safari.app/Contents/MacOS/Safari
When you need to access your bank.
Another option is to go to the Java Preferences and activate the Java Console. You can then poke around at what class there are and then write a policy file that jails that applet. Not sure how easy this would be. Your best bet would be to make the policy system wide in the current JVM by installing within the classpath under /Library/Java/Home"
