I've seen quite a few selling MP4 players on many forums. Could someone kindly explain to me what are their uses? Ive seen most can play videos, read txt files etc. Since the use is so good, why does it seems not many pple are using it? And the prices are fairly cheap too. $120 for a 256mb. With a player that comes with so many functions, why is it not popular? Is it being big industry players like IPOD and Creative hasn't come up with any of these yet so pple are still unsure of whether to buy or not?