Techware Labs has made a review of the Samsung Yepp 90S MP3 Player :
With the market for portable digital audio players growing and many different brands and kinds of players on the market the Samsung Yepp-90S stands above many of the current ones. Being so compact in size and allowing overall good audio performance and extra features this product is a cut above the rest. Being very customizable as well which is always a consumers dream the Yepp-90S is in a market of its own. Its bigger brother the Yepp-90H which is basically the exact same player except for the fact that it has 128MB of built in memory instead of the 64MB available in the Yepp-90S.
What would have been nice and is kind of disappointing is that fact that there is no place for the expansion of storage on this product. Many other MP3 players do come with some type of storage expansion like a smart media card.