The Asus PadFone is an Android device that snaps inside a PadFone Station tablet, which can connect to a keyboard, for a smartphone-to-tablet-to-notebook experience.

More than a 4.3-inch smartphone running Android Ice Cream Sandwich, the Padfone is one of a family of complementary devices. It clicks into a 10.1-inch PadFone Station tablet, which can click into a PadFone Station Dock, letting a user move seamlessly between smartphone, tablet and netbook experiences.

The Asus PadFone measures 5 by 2.6 by 0.36 inches, and weighs 4.5 ounces. It features a 1.5GHz dual-core Snapdragon S processor, an 8-megapixel rear camera, a VGA front-facing camera and a quarter-high-definition (qHD) 960 by 540 Super AMOLED (active-matrix organic LED) display with a capacitive multi-touch panel and Gorilla Glass. WiFi, 3G, 4G and Assisted GPS are all supported.

It can also be used with a special stylus—though more on that in a moment.

Asus’s touted Dynamic Display technology means users don’t need to be cautious about booting up one device inside another; a user can start a video on the phone, slip the phone inside the tablet and the video will resume where the viewer last saw it.

Asus calls these devices symbiotic, but they’re arguably parasitic instead. The smartphone charges while inside the tablet, and in addition to showing that video on the large screen, it makes use of the tablet’s larger, louder speakers as well. The tablet, when clicked into the dock, likewise begins drawing a charge. The PadFone’s battery is extended by five times with the Station and nine times with the Station Dock.

Another neat feature is the PadFone’s “one-stop storage,” which means all things are equal across devices. There’s no need to sync. Pull the PadFone from the tablet and all the same data is on board.

What happens when you get a phone call? You can take it on the PadFone’s Bluetooth headset—which, transformed, is also the stylus.

The PadFone is expected to begin shipping in April, though pricing and other details have not yet been revealed.