new file mode 100644
--- /dev/null
+++ b/hex2chars.c
@@ -0,0 +1,139 @@
+/**
+ *     $Id: hex2chars.c,v 1.1.1.1 2008-04-28 17:32:53 mbroeker Exp $
+ * $Source: /development/c/demos/hex2chars.c,v $
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#ifndef RUNS
+#define RUNS 16
+#endif
+
+/*
+ * =708== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 13 from 1)
+ * ==708== malloc/free: in use at exit: 352 bytes in 32 blocks.
+ * ==708== malloc/free: 48 allocs, 16 frees, 3,680 bytes allocated.
+ * ==708== For counts of detected errors, rerun with: -v
+ * ==708== searching for pointers to 32 not-freed blocks.
+ * ==708== checked 68,684 bytes.
+ */
+
+const char *characters = "xuzicjklmneopbdaqfrstvgwhy";
+
+char *remap_works (char *str, int slen)
+{
+    int i;
+    int pos;
+    static char *s;
+
+    if ((s = malloc (slen + 1)) == NULL)
+        return NULL;
+
+    for (i = 0; i < slen; i++) {
+        if (str[i] >= 'a') {
+            pos = str[i] - 'a';
+            s[i] = characters[pos];
+        } else {
+            /*
+             * Let numbers asis
+             */
+            s[i] = str[i];
+        }
+    }
+
+    s[i] = 0;
+    return s;
+}
+
+char *remap_works_not (char *str, int slen)
+{
+    int i, j;
+    double value;
+    double *table;
+    static char *s;
+
+    int clen = strlen (characters);
+
+    if ((s = malloc (slen + 1)) == NULL)
+        return NULL;
+
+    if ((table = calloc (clen, sizeof (double))) == NULL)
+        return NULL;
+
+    for (i = 0; i < clen; i++)
+        table[i] = cos ('a' + i);
+
+    for (i = 0; i < slen; i++) {
+        if (str[i] >= 'a') {
+            value = cos (str[i]);
+            for (j = 0; j < clen; j++) {
+                /*
+                 * flip and expand characters
+                 */
+                s[i] = '*';
+                if (value == table[j]) {
+                    s[i] = characters[j];
+                    break;
+                }
+
+                if ((fabs (value - table[j])) < 0.001) {
+                    s[i] = characters[j];
+                    break;
+                }
+            }
+        } else {
+            /*
+             * Let numbers asis
+             */
+            s[i] = str[i];
+        }
+    }
+
+    s[i] = 0;
+
+    if (table != NULL)
+        free (table);
+
+    return s;
+}
+
+int main (int argc, char **argv)
+{
+    int i;
+    int len;
+    char *start;
+    char *end;
+
+    if (argc != 2) {
+        printf ("Usage: %s <string>\n", argv[0]);
+        exit (0);
+    }
+
+    start = argv[1];
+    len = strlen (start);
+
+    printf ("\n  --- REMAP_WORKS FINE ---\n\n");
+    for (i = 0; i < RUNS; i++) {
+        if ((end = remap_works (start, len)) != NULL)
+            printf ("%s\t<==>\t%s\n", start, end);
+        start = end;
+    }
+
+    /*
+     * reset state
+     */
+    start = argv[1];
+
+    printf ("\n  --- REMAP_WORKS_NOT because floating-point comparison is evil at all ---\n\n");
+    for (i = 0; i < RUNS; i++) {
+        if ((end = remap_works_not (start, len)) != NULL)
+            printf ("%s\t<==>\t%s\n", start, end);
+        start = end;
+    }
+
+    return 0;
+}