Now you can tell your friends what you are doing or how you're feeling right this minute by changing your status message on your profile and letting it show up in your friends' homepages.
If you prefer to keep your updates private, we give you the option of not showing your friends your updates. To prevent your updates from appearing on your friends' homepages, go to the Privacy Settings page and select 'hide updates' under the "my updates" section. If you don't want to see updates from your friends, select the "don't show updates from my friends" option under the "updates from my friends" section on your homepage. But if you ask me, with all the cool comments I get on my new photos and the scraps I receive in response to my other updates, I'm not going near these settings!
Source: Orkut Blog.