The intercity bus system in Greece is very efficient and if you do your homework you can travel anywhere in the Greek mainland with the "KTEL" (intercity) green colored buses. Every city has a KTEL bus station and the locals would be happy to direct you. The bus system was never created to accommodate tourists so you might run into the language problem. Best thing to do is to find one of the other Greek travelers who speaks English and ask for assistance. Most young people in Greece speak a little English and most would be more than happy to assist you.
Most cities offer multiple departures per day to and from Athens. Connections between other cities that are not on the route to Athens and the largest cities are more infrequent. The buses are clean and safe, with no standing passengers allowed. You have to buy your ticket at the station before you get on the bus, and you can take a small carry-on bag with you in the cabin but large luggage has to be stowed in the luggage compartments. Luggage is weighed and fees for excessive weight might be imposed. The weighing of the luggage takes place right next to the parked bus in the station.
The official Greek Interstate Bus system site (KTEL)
The official Athens Urban Transportation Organization (Athens bus routes and bus numbers)
Getting to the islands would require either a short flight from Athens or Thessaloniki, or a boat ride of varying length. Most flights from Athens are at most thirty minutes long.
For islands close to mainland hopping on a ferry is your best option. Keep
in mind that most of the ferries may make several stops on different islands
en route to their final destination. Many islands have airports and you can
catch a short flight from Athens
International Airport or Thessaloniki.
Islands close to Piraeus are connected with "Flying Dolphins" (catamarans) that are very fast and efficient. They don't offer the charm of seafaring, but will take you to your island fast.
From the 16 international airports of Greece only Athens and Thessaloniki receive regular flights from abroad. All other airports in the islands and towns of the mainland are served by frequent connecting flights from the two large cities and during the summer they accommodated numerous charter flights. The distances within Greece are small, so the furthest destination would be about half hour flight from Athens. The Greek carriers Olympic Airways and Aegean Airlines offer the majority of flights within Greece.
Renting a car in Greece is easy and inexpensive. You will find the major international car rental companies and smaller ones in the airport and in major cities, especially in popular tourist destinations. In most islands, once you get off the boat you will find that the nearest streets to the peer is lined with travel agents and car/moped rental companies. Make sure that the price you are quoted includes all taxes, insurance, and fees (such as airport fee.)
The most popular way for visitors to get around in the islands is by moped. You can rent one in just about any small town in Greece, and at about €20 per day, they are a bargain. To rent a moped usually one has to exhibit a driver's license (a Greek or international license is not required most of the time), pay the daily fee, and to leave a passport as guarantee that the moped will be returned.
While renting a moped is the most efficient way to get around the immediate area, they do become dangerous in the hands of an inexperienced driver. While most opt for the complete freedom of feeling the wind through the hair, wearing a helmet is strongly advised. The roads around Greece, and especially around the islands, are narrow, ill maintained, and car drivers drive like, well, Greek drivers. Mopeds are responsible for many tourist visits to the emergency room every year.
I do not recommend renting a moped in Athens or in any of the other big cities. It's an option best considered in the small islands. Even experienced motorcycle riders would find driving around Athens a major hazard.
In Athens the best way to get around is on foot and with the newly built Athens Metro. For destinations out of the Metro's reach getting in a Taxi would be the best option.
Taxis in Athens are very hard to flag down, and would only stop to pick up passengers if they head towards their general direction (which is illegal, but don't waste your vacation on taxi disputes.)
Taxis in Greece are allowed to pick up passengers at will until the taxi is full. This means that you can still try to flag a taxi that already caries passengers and see if they are heading your way, and it also means that if you get in a taxi as the sole passenger you might find yourself in the company of several other travelers that head in your general direction. Everyone pays their fare, so if you get in a Taxi and the meter already has 2 euro on it, and when you arrive it says 6 euro, you would only pay 4 Euro for your fare! Simple math.
Every ride must have the taxi meter running from the moment the passenger gets in. The driver will turn the meter on (which will kick in the automatic payment, so don't panic if it does not start at zero,) and you are not expected to leave a tip.
Most taxis have GPS units in them, and most taxi drivers know how to get around Athens, but telling them an exact address, might not help you in some cases. Be prepared to know the general area of our destination as well to avoid misunderstandings since a street name might exist in several different areas.
Some enterprising taxi drivers frequent major hotels and tourist hubs and will offer tours around Greece for a price. Make sure that you have a complete and clear agreement about all chargers before you enter such a deal.
To flag a Taxi, stand on the side of the road goes towards your destination. When you see a taxi approaching at a reasonable distance raise your arm and stare at the driver.
If he is not carrying any passengers he will stop an would expect that you tell him your destination before you get in, so he can decide if it is worth taking you. The correct think to do is to open the passenger door (or the back door if you prefer) get in and then tell the driver where he should take you. He should turn on the meter at this point and lower his flag (although the taxi flag is kind of a meaningless sign in Greek taxis).
If the taxi you are flagging down has other passengers in it already the taxi driver will slow down near you so you can shout your destination to him/her through the passenger window. If he stops, it means your stop is before, or a little bit after his final destination. Get in the taxi and note the amount already on the clock. Many taxis have electronic clocks that track multiple fares so you don't have to worry about this part. The tricky part here is to make sure that your destination is in concert with the other passengers' destinations so you will not be taken for a ride around Athens needlessly (and pay for it).
In key points in the city, like train stations, metro stations, ports, airports, etc., you will find taxi stations (ask a local for a "piátsa taxí"). You have to enter the first taxi in line and then tell him/her where to take you.
Taxis in small cities in Greece are less complicated. They usually are stationed at strategic points in the town and don't just drive around to be flagged. Just ask a local for the Taxi "piatsa" (station)
For a fee, you may also use "radio taxi" to pick you up at your place. You call the taxi company (use the general information phone number 11880 to find a radio taxi in your area), and they will pick you up for a fee plus the price on the meter plus a small fee for the radio call. We used Cosmos Taxi that responds all over Athens and the service was always prompt and the drivers very courtious and helpful (The phone number is 18300).
Including donkeys here under "transportation" is obviously a joke, since donkeys are not really used for transportation.
Donkeys are used on many islands for rides but mostly to take tourists around for a stroll. In Santorini for instance you can climb up to the town from the harbor either on a donkey, or a cable cart. On many small islands few locals still use donkeys for transportation since they are very efficient on steep narrow streets.
Also see: Prices in Greece