I don't duggest that , because if you go to kensignton or other ram seller, they usually have a separate section for mac or pc ram. my father tried to use my imac's ram in his PC and it worked.... kind of.... it crashed his computer every other hour, but it worked. so my guess is there are not many different harware differences in pc/mac ram but enough to make the trip unpleasant. so, buy mac ram not pc ram.
unless you are talking about the NAME of the ram, like: PC133 or PC66 etc, in which case, ignore my post.