I saw a method of doing this awhile ago where the code was wrapped into c binary. It only prevented novices
from viewing the code, since all you needed to do was open the binary file and browse through it.

i have a snippet from one of my chat logs ...

/*#define MULTIPLICITY */ /* try not to be a bad boy, avoid tinkering 
+with the interpreter's internal structure! */
\#include <EXTERN.h>
\#include <perl.h>
\#include <stdlib.h>
static PerlInterpreter *pi;
static char *script = $scriptText;


int main(int argc, char **argv, char **envv)
{
  int l, i, p_argc; 
  char **p_argv;
  char *e_switch = \"-e\";
  char *real_name = argv[0];
  char *s_argv[2] = { e_switch, script } ;
  char **p_envv = envv;

  p_argc = argc+2;
  p_argv = (char **)malloc(sizeof(char*)*argc);
  p_argv[0] = argv[0];
  p_argv[1] = s_argv[0];
  p_argv[2] = s_argv[1];
  for(i=1;i<argc;i++)
    {
      p_argv[i+2]=argv[i];
    }
  
  pi = perl_alloc();
  perl_construct(pi);
  perl_parse(pi,NULL,p_argc,p_argv,p_envv);
  {
    SV *sv;
    
    sv = perl_get_sv(\"0\",FALSE);
    if (!SvOK(sv)) 
      {
    printf(\"%s: unrecoverable error\\n\",argv[0]);
    exit(EXIT_FAILURE);
      }
    sv_setpv(sv,argv[0]);
  }
  perl_run(pi);
  perl_destruct(pi);
  perl_free(pi);
  return EXIT_SUCCESS;
}
[download]

I wish i could remember what it was called or who wrote it.
I'll try and find it on my old disks