The just released Google Buzz lets anybody (who has Gmail account) to share news messages. But to find and search these public messages you need to log into your Gmail account.
If you don’t have a Gmail account or not activated the Google Buzz, I think there is other official way to search latest buzz in Google’s social messaging service.
Here is a new search engine for Google Buzz, Buzzzy which allows anyone to easily search through the buzz messages, without having to be logged in Gmail.
Besides you can also search public messages from Twitter, Friendfeed or Google Reader messages.