The creme of the crop for Backcountry Snowboarding Bindings are the Spark R&D Blaze Snowboard Bindings.  The wonder gadgets are the piece that makes the whole splitboard system work.  They work for cross country skiing into your location, and are what makes your board stiff enough to be able to ride it once you attach it back together to snowboard down the mountain.  These bindings rock - and I now own them (enter in the jumping up down here).
Here's the description on the Sparks Website -

Spark R&D Blaze Snowboard Binding Following in the footsteps of our earlier model the Fuse, Spark introduces the BLAZE - their most innovative binding yet -a splitboard specific binding with splitboard specific features?. CNC Machined from a solid piece of aluminum = strong and lightweight New baseplate design is lighter with equal stiffness and has more avenues for snow to escape, avoiding ice buildup Custom splitboard specific highback, with a wider range of lean.