For what it's worth, the iPhone has one there.

I've noticed that a number of personal translator devices (still a popular category of device, despite the capabilities of cell phones) have handwriting interfaces.

(The "in Korea, handwriting interfaces are for old people" meme is struggling to escape, but I need to keep telling myself this isn't slashdot. People are actually intelligent here)

I know they don't in Korea. Hangul lends itself to typing.