Facebook on Thursday launched Friendship Pages at which online pals can stroll virtual memory lanes that chronicle what they have shared at the world's top online social networking service.

The pages contain public comments and "Wall" posts between pairs of Facebook friends; pictures in which both are identified; events they indicated they would attend together, and other joint activities memorialized at the service.

"When it's between two people who share a lot, the page really starts to reflect their friendship," Facebook software engineer Wayne Kao wrote in a blog post announcing the feature he played a key role in creating.

"The best part is the human side of these pages," he continued. "They can bring back memories, conversations and times spent together."

Others will only be able to view the nostalgia pages with the permission of those featured, according to Kao.