The Kyocera Echo, Sprint’s new Android 2.2 (Froyo) smartphone — with two displays stacked on top of one another, Nintendo DS style — is now available for pre-order. Interested customers can reserve the Echo for $199.99, after a $100 mail-in rebate, for delivery on April 17th. We went up close with the Echo during CTIA last week, and we enjoyed the device’s second screen — which can double as a large touchscreen keyboard, enhance game-play, and more. Sprint says “quantities are limited,” hit the jump if you’re interested in reserving yours now.