Enjoyed reading this thread.  I am also trying to decide between a Canon Powershot S5 IS and the 400D/XTi.
  Can anyone suggest a good second lens for the 400D/XTi  for telephoto work.   The standard 18/55 lens would be ok for a lot of shots but I would want a nice lens for telephoto work.    Where is a good place to buy this lens and not cost an arm and a leg to get. :)

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