You should now be able to tag a friend by simply typing the @ symbol which will automatically reveal a drop down menu with a list of your friends and other connections including groups, events, applications and pages. You’ll soon also being to tag friends in applications too.
Notably, the “@” symbol will not appear on the status update after you’ve pressed to submit it which should help with not over complicating status updates and such.
Friends you tag in your status updates will receive a notification and a Wall post linking them to your post. They also will have the option to remove tags of themselves from your posts.
More info on the feature here.