I've hiked in Greece. One thing you should really do is go to the Anavasi map publisher and bookstore, 210 72 93 541, Stoa Arsakiou 6A (corner of Panepistimiou and Arsaki) in Athens and buy the 1:250,000 map for the Peloponesus. Then get a simple GPS (Garmin Foretrex 301 is what I recommend) so you can find yourself on the map. Mapping GPS's are more trouble than they are worth outside the main cities. All you need is a GPS that can find your position accurately so you can find yourself on the paper map. Turn the GPS on when you need a position fix, then turn it off afterwards. If you use it like this, a single set of AAA batteries will last for several months with the Foretrex 301.

Anavasi maps use GGRS87 (Greek Geodetic Reference System 1987) datum. If GGRS87 is not listed in your GPS device, then use the following settings (grid describes the transverse mercator projection from latitude-longitude to GGRS87 northing-easting coordinates, datum describes the Molodensky transformation from WGS84 ellipsoid to GGRS87 ellipsoid):

* User Grid: Longitude origin=+24.0E, Scale=.9996, False Easting=+500,000, False Northing=0
* User Datum: Dx=-200.1, Dy=73.9, Dz=246.0, Da=0, Df=0

Much of the E4 trail that I hiked in the Peleponesus was over dirt roads. Very little traffic. Occasional farmes in their vans rolling at 10mph on their way to/from an olive grove. Beautiful country in the spring when I walked through. Too bad it all burned that same year in the summer.

Crete is also very good for biking, or so I heard from other travelers there on bikes. The hiking trail I took was mostly a true mountain foot-path and totally unsuitable for bikes. But occasionally I walked on country roads, some paved, some dirt. All of these roads where very quiet. Anavasi sells 1:100,000 maps for Crete.

Anavasi maps are the best, but Road Editions is another possibility. Their office in Athens is Solonos 71 (corner Ippokratous). There are also Harms and Rough Guide maps for Crete.