orkut's blog announced that there's another way to view the birthdays: in Google Calendar. "Now, in conjunction with Google Calendar, you can see all of your orkut friend's birthdays for the whole year. If you've already used Google Calendar before, you will shortly see a link (right below the "upcoming birthdays" section) where you can add your orkut friends' birthdays to your Google calendar."
If you don't see the promotional link, use this URL to subscribe to the calendar. Google uses a special kind of calendar that requires authentication and doesn't support notifications. That means you won't be able to receive email or SMS notifications that remind you of the birthdays.
{ via orkut blog and ToThePC. }