This is just a function I came up with in about 1 minute and thought I would share it with the community. It has no real practical use, so take it as something to learn from.
#include <Constants.au3>
MsgBox($MB_SYSTEMMODAl, '', CreateGUIDFromString('Some very simple string.'))
MsgBox($MB_SYSTEMMODAl, '', CreateGUIDFromString('A GUID string.'))
MsgBox($MB_SYSTEMMODAl, '', CreateGUIDFromString('1 chr'))
; #FUNCTION# ======================================================================