OCR works with the newer iPod touches, so if you are going to buy one of those for pleco then you will not need an iPhone just to use OCR. so when you do get your ipod you should be able to use the demo to see if its useful for you.
for me, i am taking chinese classes at jiao tong in shanghai, but not for a degree. i bought it because i thought it is really cool and it is, but in practice i find that i do not use it as much as i thought i would (i thought i would be using it all the time). the most useful thing for me was to create flashcards from my textbooks, being able to do that saved me a lot of time. for my studying, i know most of the words in the book already so when i do need to look up characters i dont know, sometimes it is faster to use the handwriting feature as opposed to going to the OCR; part of that is that it is faster to use the dictionary which i am in most of the time, as opposed to clicking through to the OCR function. I find that it is more useful for everyday life here in China as I can take pictures of menus, newspapers, flyers, etc and use the block recognizer and scroll capture text to read them later. For those uses a lot of times i do not know a lot of the words and it is much easier to use OCR to read those.
overall, for me, it was worth it because it saves me time with making flashcards and the ability for me to take pictures of stuff and read it later.