--- a/UUID.st	Wed Feb 24 11:09:08 2010 +0100
+++ b/UUID.st	Fri Mar 05 15:57:14 2010 +0100
@@ -576,6 +576,29 @@
     "
 ! !
 
+!UUID methodsFor:'hashing'!
+
+hash
+   "Generate a 30 bit hash value.
+    For Timestamp-UUIDs:
+        Bytes 1,2,3,4 are the least significant bits of the timestamp,
+        Bytes 14,15,16 are the least significant bytes of the mac address - 
+            but considering these bytes does not generate a better hash to
+            justify the additional computations.
+
+    For random UUIDs, every byte is random anyway."
+
+    ^ (((((((self basicAt:2) "bitXor:(self basicAt:14)") bitShift:8)
+        + ((self basicAt:3) "bitXor:(self basicAt:15)")) bitShift:8)
+       +  ((self basicAt:4) "bitXor:(self basicAt:16)")) bitShift:6) bitXor:(self basicAt:1)
+
+    "
+        |allHashes|
+        allHashes := UUID allInstances collect:[:each| each hash].
+        (allHashes asSet size / allHashes size) asFloat
+    "
+! !
+
 !UUID methodsFor:'printing'!
 
 displayString
@@ -656,7 +679,11 @@
 !UUID class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.30 2009-06-15 12:43:41 stefan Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.31 2010-03-05 14:57:14 stefan Exp $'
+!
+
+version_CVS
+    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.31 2010-03-05 14:57:14 stefan Exp $'
 ! !
 
 UUID initialize!