There are several programs you can use to view flashcards on your ipod. Google will yeild results.
However there is no port of Anki for the Ipod, so the best you can do will be to import your cards into one of these programs, but you will not get the benefits of srs.
I generally find the hassle of using flashcards just isn:t worth the hassle compared to a pc. On the go time I just read or listen to Japanese. Its still practice.