I use my iPhone, so I'm assuming it's basically the same as using an iPod touch...
Anywho, I love it. It means I can take KC101 with me wherever I go, and listen to it whenever I can! ^_^ Often, I listen after I've gone to bed, as I seem to remember things well after midnight.

But this is great - I just lie down, get comfy and listen! =D I also use it while I'm driving and on public transport. It's also good if you're walking somewhere. So, really... it just means KC101 is portable and you can take it with you! ^_^
Personally, I think it helps me learn better, as learning a language requires you to do a bit everyday, and if you're using a computer, that can be hard, as you can't always be at your computer. But having lessons that are portable means that you can do a bit everyday, no matter where you are.
I don't really have any limitations... it's just generally very handy being able to go anywhere and have Korean lessons with me wherever I go...! ^_^
Also: I'm not sure about the iPod touch, but having an iPhone means I also have access to the internet wherever I am, hence making it all the more easy to access this website!
I hope my reply was somewhat useful! XP