The 512M and 1G memory stick Pro Duo from SanDisk are now both cheaper than ever, and quality is just as good (if not better as seen on many product review) than the official Sony version.
<a href="http://www.divineo.cn/php/affstart.php?affcode=arboretum&prod=misc-mem1GB"><img src="http://www.divineo.cn/divineo/images/products/misc-mem1GB-s.jpg" border="0" alt="Sandisk Mem card"></a>
The price for the 1gb is $ 109.95 (cheaper than mine )