Most of the ppl hide their id on orkut or their id is only shown to their friends
so do u know that u also can get their mail id by this step’s

first add the target person as a friend (by going to his orkut profile).
Click on “ignore user” on the top-left corner.
open google talk.
Go to setting.
in setting click on blocked

under blocked u get the mail id of that person…
Person id z Traped