GreenThumbelina: Having also lived in Tokyo, I was also a little frustrated at the brevity of the blossom period. In Tokyo most of the trees seem to be of the same "Yoshino" variety; so they all bloom and fall at the same time. In England there seems to be more diversity of cherry which makes for a more drawn out season, though one that is at no point as spectacular as that in Japan.
Happymarion: in case you don't already know, many of the cherry trees in Washington DC were a gift from the Japanese government.