We noticed in orkut, Google chat is rolled out side by side and some of the users can see chat is enabled.

Now you can start chat with your friends in orkut after Google chat is enabled for your account.

Google Talk features allows you to

• Chat with orkut users and friends
• You can send messages instantly in real-time.
• chat with your Google Talk contacts and Gmail contacts from orkut.
• While chat box is opened you can browse through Orkut.

Just check your My settings option in orkut you can see a tab called chat where you can invite your friends and start chatting.

Thanks toTech-Buzz