Where will Samsung put their Touch ID?

We all know it's inevitable that Samsung and others will add their own fingerprint scanners in the wake of Touch ID. But they will also face challenges, such as matching the security of the A7's "secure enclave" and its 64-bit cryptography that is used to encode your fingerprint data and enable almost instant unlocking.

What I really can't imagine is where Android handset makers will put their scanners. Apple has kept their home button over the years despite some criticism and has now found a whole new use for it. By contrast, almost all Android phones have gone to an on-screen button design with very narrow top and bottom bezels. I don't see an obvious place for a scanner on any current model phones. This seems to present a bit of an issue.

What do you think Samsung, HTC, and others will do to copy the Touch ID? Will they have to significantly modify the Galaxy and HTC One designs to accommodate one?