I have a 1st gen iPhone, and when the 2.0 software was released, I jumped on the "international keyboards" option (screenshots below).
Japanese entry is a kana keypad (arranged like a 10-key phone pad: a is 1, ka is 2, sa 3, and so on, with wa, wo, n, and [dash] at 0). Touching ka (2) will pop up a four-way choice: ka in the middle, ki to the west, ku to the north, ke to the east, and ko to the south. Typing wa-ta-shi will pop up a bar with the kanji and several other choices. After converting kana to kanji, often some suggested particles will pop up. It's about like the Windows IME in responsiveness, I guess.
However, if you also install the Chinese (traditional) keyboard, you can write kanji with your fingertip. This is fun, works with about 99% of the kanji I've tried so far, and also really reinforces stroke order. With left-right kanji, you can also draw the left half, accept its guess, then draw the right half, and usually it will pop up a choice that shows them combined. This is useful for very complicated kanji, since a fingertip is not a super precise writing tool...
I've bookmarked a couple of J-E/E-J online dictionaries and when I have a spare moment, I entertain myself with trying to recall and write random kanji and then looking them up.
I really can't speak to the suitability of the iPhone to the Japanese market, but here in Austin, it's my portable study toy. :-)
Japanese keyboard
Chinese (traditional) keyboard (Notice that it has corrected my slightly misdrawn kanji)
Last edited by annabel398 (2008 August 20, 7:26 pm)