u can write down the Korean language alphabates on the memo pad or the make a word doc, sync it on your device and use the memo or the word doc whenever u need, i guess if u don't find any Palm application, this is going to help u out !
You might already know this, but Korea speakers buy a program to enable them to write in Korean in the graffiti space for entering info onto the pda in Korean graffiti ("diopen").
the same site that sells the Korean language support for the pda also sells an English-Korean, Korean-English dictionary ("e4u dic"). Unfortunately, i don't think this dictionary has a "hanja" (Chinese characters) dictionary.
Not exactly the flashcard thing, but i think it "remembers" the last words you looked up so you can go to that screen to review words that you didn't know.
OOPS! I just realized that you are trying to memorize the ALPHABET itself!
Well, in that case, maybe you can wait to get the dictionary (until when you are reading documents in Korean and trying to expand your vocabulary)
sorry for the not-so-helpful at this point in time response... but i'll leave this post here just in case you further your Korean language study and eventually need a korean-english, english-korean dictionary...