If most of your friends and family members have a presence on Orkut, you’ll be happy to know that you can now track their birthdays in Google Calendar.
To get started, click this link and it will automatically add a new Orkut Friends’ Calendar to your existing Google Calendar.
Unlike the Orkut website that displays only upcoming birthdays, this Google calendar of Orkut Friends will let you navigate both forward and backward so you can even see "belated" birthdays that you might have missed before. More details on the Orkut blog.
While most Orkut users will definitely find the calendar feature useful, there’re limitations. For instance, you can neither subscribe to Orkut birthday notifications in Google Calendar via SMS or email, nor do they provide an XML or ICAL feed for the Orkut calendar so you can’t import birthday notification into other calendar systems.
The only workaround is Google Calendar Sync that will help you import Orkut birthdays into Microsoft Outlook calendar from where you can copy the events into other calendars like Yahoo! or 30 boxes.