Not sure if this is still present, but the first intel release had this mapped into ever process's address space:

$ cat dsmos.c

main() { puts(-16 * 4096 + 0x1600); }

$ gcc -o dsmos dsmos.c

$ ./dsmos

Your karma check for today: There once was was a user that whined his existing OS was so blind, he'd do better to pirate an OS that ran great but found his hardware declined. Please don't steal Mac OS! Really, that's way uncool. (C) Apple Computer, Inc.U??VWS?5P

From the excellent:

http://www.osxbook.com/book/bonus/chapter7/binaryprotection/