root@hesthagen:/home/henrikau/dev/test/crap# cat -n perm_bits.c 
     1  #include <stdio.h>
     2  #include <stdlib.h>
     3
     4  int main(int argc, char *argv[])
     5  {
     6    printf("hello world\n");
     7    return 0;
     8  } /* end main */

root@hesthagen:/home/henrikau/dev/test/crap# ls -l
totalt 12
-rwxr--r-- 1 root root 6897 2007-07-23 10:30 perm_bits
-rw-r--r-- 1 root root  131 2007-07-23 10:29 perm_bits.c

henrikau@hesthagen:~/dev/test/crap$ ./perm_bits
bash: ./perm_bits: Permission denied
henrikau@hesthagen:~/dev/test/crap$ /lib/ld-linux.so.2 ./perm_bits
hello world