I have been getting a lot of hits recently for people searching for the meaning of the Greek flag. Since I don't think I've discussed it before, I'll make it short and simple for the folks that are actually looking for an answer.
The stripes represent the syllables in the phrase "Eleftheria i Thanatos" (Freedom or Death), which was a morale boosting chant during the Ottoman occupation. The colors represent the beautiful sea surrounding Greece, and the cross is in honor of the Orthodox Church. In short, a lovely flag for a lovely country. The only thing that would have made it better in my eyes is if it was purple and blue instead of white and blue. When I have my own country, maybe I can design an all purple/blue/black flag. We can nickname it "the black eye".