[tsbtx]

No, I don't believe you could upgrade the 4gb without some VERY serious soldering, and software changes. 4gb is good as is, the read/write time is awesome.

One thing I am curious about is I have seen people who have written programs to use the TransFlash SD cards as expanded memory for the handset itself, draw back being the limited read/write of flash memory. The Diamond doesn't use it, so I don't see why you couldn't even attempt to run Windows XP on the thing (joking). The memory shouldn't have a limited read/write cycle meaning if you did have a way of partitioning the memory you should be able to dedicate some of it to WinMo and not have it die off.