In reply to keithlambley:
Have you been to Kaly before? If not, and depending where you are staying, you are probably better off managing with the local buses and from Massouri or Myrties you can walk to many of the best crags. If you are planning to climb on Telendos for a couple of days, as most parties seem to do now, then your car will just be sitting by the jetty all day. If you want to climb in the Vathy valley (E.T, Rockland etc.) or Paliosonas Bay and/or Secret Garden then either hire bikes or a car just for 2 or three days. With a little forward planning this works out much cheaper.
A car is only really necessary if you staying at Kantouni or Panormas but even here the buses can be used with a little more disciplined planning. The buses are very cheap.
Dave