Ever wanted to be able to compile your shell script for whatever reason? Well, there is this cool utility called shc that when ran, compiles your plain text shell script into a "C" executable binary. You can even pass the -e option too give it an expiration date which will refuse to run after the date specified.
Go and try it yourself:http://www.datsi.fi.upm.es/~frosal/
Of course, like any and all software, it wont stop the most determined individuals from reverse engineering the executable.