It is diffcult to find online friends in Orkut ,specially for those who are very new to orkut ,but after reading this post all your problems and issues on this get solved ,read below post carefully to understand that. 
When you view your friends by clicling my friends box on the right-hand side of your homepage, the orkut members who have recently logged on are featured at the top of the page.
You can see an alphabetical list of all your friends by clicking the “Friends” link in the blue bar at the top of the page. 
When you view other users profiles, you will see their recently logged in friends at the top of the page. While Orkut usually feature your most active friends at the top, keep in mind that orkut friend order isn’t an exact science and they sometimes mix up who logged in last !
In orkut, after login, in your friends list, you can find the most recent online friends from top left to right in a first row. But that doesn’t guarantee that the friend is online now. In order to find out the friends online, it better to look for those small circle below your friends. If its green then that means your friend is online in GTalk. If its red, then he/she is Busy and if he is offline, the circle color is off.
But these small circle will be shown for only those friends who has got Google Account i.e. GMail Account.
