In a recent announcement, Facebook has made the default privacy setting for status updates visible to “everyone.” What this means is everyone on the Internet, not everyone of your friends. The reason behind the change is Facebook’s desire to increase it’s visibility in search engines and to compete more directly with Twitter (where public updates are also the default setting.) It’s not hard to keep your old settings, but there is a lot of confusion about their interface and what the term “Old Settings” really means. Learn more at ReadWriteWeb.com .

On October 1, 100,000 lucky users got an invitation to preview Google’s new real-time communication platform: Google Wave. It combines email, instant messaging, chat, project management and social networking in a client that sits within the browser. To learn more, read Mashable’s guide or watch Google’s video .

Follow Friday, often abbreviated as #FF, is a weekly Twitter tradition of calling out your favorite tweeps (Twitter people) as a way of recommendation. According to Mashable , its history can be traced to Twitter user @micah who invented it on January 16, 2008.

For Twitter power users, the single-tasked Twitter Search (http://twitter.com/search/ ) may not be enough of a good thing. TweetGrid allows you to define a custom grid of Twitter search results, such as 1×2 or 3×3, each cell displaying different search results. TweetDeck is a multi-column Twitter client that also gives you the option of displaying multiple search results at once.

Although technically neither spam nor phishing, those aggressive emails from Tagged claiming a friend has sent you photos are certainly pushing the limits of netiquette. Ask Leo explains how Tagged.com got your email address and know your friend’s name, and why you should simply ignore them.

Gravatar is a service that provides a “globally recognized avatar” that follows you from site to site, identifying your comments and posts across the web. The free service currently works with Wordpress, SezWho, and many other services. Chris Pirillo explains more in this video “Is Your Avatar a Gravatar?.”