[JTM]

I'm actually curious about this as well.

In the past I've found some of the Nintendo DS Kanken programs/games like Kanji Sono Mama Rakubiki Jiten 「漢字そのまま楽引辞典」, 250 Man Nin No Kanken 「250万人の漢検」 and Nazotte Oboeru Otona no Kanji Renshu 「なぞっておぼえる大人の漢字練習」 very helpful but it is somewhat embarrassing for a guy to pull out a NDS and work with it.

I've dabbled with some of the iPod Japanese language apps and have found them to be very good as well like CodefromTokyo's Nihongo Jisho, Shogakukan's Daijisen Nihongo Jisho and JISHOP's Advanced Jisho. I also kind of like the JLPT tutor programs. I like the fact that these are updated every so often so they are kept fairly current but all the good Japanese Language assist programs are indeed expensive.

With the new iPhone G4 out I wonder if functionality/response time will improve with that.

I don't have an iPad yet but it would be interesting to hear how these apps work with that.