Memory doesn't quite double every two years; if it did, we'd have almost 80 GB of memory by now.

Code:

$ python
Python 2.4.3 (#1, Jul 27 2009, 06:41:38)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-44)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> x = 64
>>> for n in range(0, 20):
... x *= 2
...
>>> print x
67108864
>>>

Anyway, looks like about 300 years from now, with Moore's Law still holding, we'd have about 10**45 GB of memory . . . .

Code:

>>> x = 2
>>> for n in range(0, 300/2):
... x *= 2
...
>>> print x
2854495385411919762116571938898990272765493248
>>> import math
>>> math.log(x) / math.log(10)
45.455529345261155
>>>