If you could live the day as a member of the opposite sex, what would you do? Do you think you'd want to return back to your original sex?

For all you writers out there:

Do you think it is more difficult to write in the perspective or voice of the opposite sex? Some writers seem to do it quite fluidly, (e.g., Jeffrey Eugenides in The Marriage Plot).

Do you think it's a skill honed from observation? sensitivity? knowing the opposite sex intimately? or imagination?