The iPod touch has built-in system-wide support for handwritten Chinese, but not Japanese. In practice you can use that for Japanese to some extent; maybe eighty percent or so of Japanese kanji are recognised (but of course it doesn't work for kana). However quite a few Japanese apps, such as the Daijirin, come with their own handwriting recognition support.
I don't use Epwing myself, so can't comment on that.
One advantage deshi jisho do have is that it's quick and easy to jump between dictionaries.
If you do get an iPod Touch, then the next version of the OS (coming soon) will allow multi-tasking, which should mean that jumping between apps gets a bit less tiresome. But note that the cheapest model of the present iPod Touch range (8GB) will not be able to employ that feature (a shame because you can get refurbished models from Apple for only 14,800 yen).
I don't use Epwing myself, so can't comment on that.
One advantage deshi jisho do have is that it's quick and easy to jump between dictionaries.
If you do get an iPod Touch, then the next version of the OS (coming soon) will allow multi-tasking, which should mean that jumping between apps gets a bit less tiresome. But note that the cheapest model of the present iPod Touch range (8GB) will not be able to employ that feature (a shame because you can get refurbished models from Apple for only 14,800 yen).