Greek National Tourism Organization
A good place to start, this site has information on every region of Greece and gives a good overview of history and culture.
The Mining Company's Greece for Visitors
One of the best resources I found online for down-to-earth information on Greek culture, travel tips, and anecdotes.
Lonely Planet/Greece
In true Lonely Planet form, this site tells it like it is.
Olympic Airways
Up-to-date schedule and fare information for Greece's major airline
Cheat Sheet for Travelers
Currency converter you can print out and take with you...an invaluable resource for the math-impaired!
Filitera Villas
Beautiful photos and details about our favorite hotel, including an online reservation form
Vritomartis
Info on the hotel's facilities, and phone/fax numbers in case you want to make a reservation. (No online form here, unfortunately.)
Knossos
Images from the Palace at Knossos, and links to Crete's other historical sites
Akrotiri
Photos and historical details from the Akrotiri excavation site; also has links to other Cycladic islands