Users are being encouraged to share their "thanks" with the people they connect with everyday. They can obtain the gift from the Facebook gift shop.
Facebook, which launched on February 4 2004, has evolved over the years into the world's most popular social networking site.
It has over 150m members, having overtaken rival MySpace, which has 130m.
- Average user has 120 friends on the site
- More than 15m users update their statuses at least once each day
- More than 850m photos uploaded to the site each month
- More than 24m pieces of content (web links, news stories, blog posts, notes, photos, etc.) shared each month
The site has facilitated change outside of the online community. A Facebook group formed on the site helped convince Cadbury to bring back its Wispa chocolate bar, while another group helped organise an anti-knife crime march in London last year, in which more than 2,000 people took part.
Mark Zuckerberg, Facebook founder, said his team will continue working hard, trying to build better ways of sharing information.
He wrote on his blog: "Building and moving quickly for five years hasn't been easy, and we aren't finished. The challenge motivates us to keep innovating and pushing technical boundaries to produce better ways to share information.
"Enabling efficient sharing is important because it makes the world more open, and this gives everyone a voice to express ideas and initiate change."
The site has undergone several redesigns since its launch.
"Tomorrow is Facebook's 5th birthday. This is a happy occasion for Facebook, but much more significant to the Facebook team is the fact that over 150 million people around the world are using Facebook to connect with the people in their lives.
Facebook was founded in 2004 to give people the tools to engage and understand the world around them. We are glad and humbled that so many people are using Facebook in this way.
While we at Facebook make products that enable people to share information efficiently, Facebook is mostly the product of the people who use it. Without you and the connections you make to others, the products we create wouldn't have much meaning. So we feel fortunate to have all of you with us.
To express our appreciation, we've created a "Thank You" gift, which will be available tomorrow in the Facebook Gift Shop for you to give freely to others. In the spirit of celebrating connections between people, we encourage you to use this gift to give thanks to your friends, colleagues and family members with whom you are connected on Facebook.
Since its founding, one of the constants of Facebook is that it has continuously evolved to make it easier to share. To give you a sense of how the site has changed, we dug up a few images of how Facebook used to look -- you can see them here.
Building and moving quickly for five years hasn't been easy, and we aren't finished. The challenge motivates us to keep innovating and pushing technical boundaries to produce better ways to share information.
The culture of the Internet has also changed pretty dramatically over the past five years. Before, most people wouldn't consider sharing their real identities online. But Facebook has offered a safe and trusted environment for people to interact online, which has made millions of people comfortable expressing more about themselves.
Why is it important to us to keep building better ways for people to share information? Enabling efficient sharing is important because it makes the world more open, and this gives everyone a voice to express ideas and initiate change.
As we celebrate Facebook's 5th birthday, we continue to work hard to evolve Facebook and make it as simple as possible to communicate with and understand the people and entities that matter to you."