I think that if obfuscating the source code (by compiling or encrypting or whatever) is a high priority for you, then Perl may not be the best choice of language for your software. And even for Java there are decompilers and for PHP the code must be unencrypted to run. So maybe C is the best choice.
Bleach.pm is pretty fun, as are the other ones like it. Making all the variable names difficult and easy-to-confuse; adding garbage that looks like code and making the code look like garbage; there is a lot of room to improve code obfuscators. Obfuscation and pretty-printing are two sides of the same problem. Why don't people decompile and disassemble as much as they used to? It's difficult. Obfuscation works the same way. At my company, we wound up distributing a demonstration of a system that was largely written in perl as a locked VMware virtual machine in order to draw a clear box around it. Sure someone who was knowlegable w/ vmware would be able to reset the config password on the virtual bios and so on, but the line would have been crossed, as surely as removing the hard drive and mounting it in another system would have.
