The DS has actually had a very lucrative business as a device for training/tutoring.
My nephew has down syndrome and he uses a DSiXL as a talker with this:
http://www.taptotalk.com/. He can go into McDonald's and order for himself for the first time in his life (he has no speech and only signs). Before that, he had a proprietary laptop with a touch screen that was extremely expensive every time they wanted to change or add words to the vocabulary on it.
On the language front, in Japan they have TONS of learning software. Ronalopolis got me this dictionary years ago:
http://www.amazon.com/Kanji-Dictionary-Sonomama-Rakubiki-Nintendo-DS/dp/B000O2S9VQ. It's technically Japanese to English but I can use it to draw an unfamiliar Kanji (confusing Japanese character/letter) right on the lower screen and have the top screen give me an English translation. Perfect to keep beside me when I'm playing Super Famicom games or even when I'm at the computer...I don't have to alt+tab out of what I'm doing or open a new browser tab just to look up a word every time. And that game/software has been more comprehensive than most things I've found for the computer and much cheaper.
