In reply to Ade7:
2008 Kalymnos guide on here is the most definitive. The crag shots are not very inspiring however.
www.needlesports.com/acatalog/Mail_Order_Greece_135.htm
Mind out as there could be a 2009 edition out between now and when you go and there are still lots of areas being developed. Though seriously doubt you would run out of routes to do in the 2008 edition!
Rockfax mini guide is good but (necessarily) quite selective and does not cover as many areas. Some good new lines have gone up and new areas have been opened up since it was published. However it has better crag shots IMHO.
Lots of grades have gone down in the new local definitive, to the extent that some of the 6s now feel a bit on the harsh side!
Personally I'd take both.