Otto is an upscale pizzeria recently opened by Mario Battali and partners. You'll be in the in crowd if you don't pronounce it like the name of a German man. It's OH-toe, which is Italian for "eight." It's on Eighth Street, just off Fifth Avenue, a short half block north of the beautiful arch in Washington Square.
The traditional Bellini is a mixture of peach juice and prosecco, a lightly sparkling Italian wine. The Otto version uses clementine juice instead. You should be able to find clementines in the produce department of larger grocery stores. And make sure you use real prosecco. Champagne, as good as it is, just doesn't give the right effect.