Facebook, the online social networking site, has reached its fifth birthday. Founded in 2004 by a Harvard University student, the site now has 150 million active users.
Here, three BBC News website readers explain how social networking has impacted upon their lives.
LYNNE ACKERS, 54, MERSEYSIDE, UK
I run a carers forum because three of my children have autism.
Many of the members on my forum were also on Facebook so I thought I'd give it a try.
I am so glad that I did as it has changed mine and my family's lives in such a fantastic way by bringing us all together again.
The site has helped with renewing my relationship with my eldest daughter. We haven't spoken for almost 10 years.
During that time she has had a daughter I had never met who is now nine and a half.
We talked for the first time on the chat feature and it helped pave the way for our first telephone conversation by letting us get to know each other a little more first.
My daughter told me she only joined the site to be closer to me.
It made it possible to connect my eldest daughter with her younger sister and brother and to learn about their lives since she was last in contact with them almost 10 years ago.
It has been such an emotional time for us all and many tears have flowed. Tears of happiness at our renewed relationship as well as tears of sadness for the lost years.
PAUL HUGHES, 60, BANGKOK, THAILAND
I'm 60 and I live in Bangkok, Thailand. I have been an English teacher in a private school here, but now I am retired.
Facebook had a big impact on my life because by joining I found my long lost brother Charlie who is 48 and lives in Crewe, Cheshire.
It had been about 28 years since we lost touch with each other. I had left home and travelled around the world and finally ended up here in amazing Thailand.
I have now found out that he left England too and went to live in Cyprus and eventually returned to settle in Cheshire.
I searched everywhere on the internet without success, until one day I found a picture of him on Facebook! I got in touch and he was over the moon to hear from his big brother again.
Now we both use Facebook to contact each other and Skype or MSN Instant Messenger in conjunction with our web cams to speak to each other.
You can imagine, we have had so much to talk about after all those years. He is now planning to visit me here in Thailand in March.
CARL WITHERS, HIROSHMA, JAPAN
I teach English to Japanese children and adults.
I met my girlfriend Satoko (who is Japanese) in Australia in 2006. We were both there on a working holiday visa.
After leaving Australia we both went home to our respective countries.
I said that when I got back to England I would find a job in Japan and we could be together again.
I found a job and came to Japan in September 2007. Five weeks after starting my job the firm I was working for went bankrupt. I had not even received my first paycheck!
After a couple of months it was looking like an impossible task to find a new job. I wanted to stay because of my girlfriend, but it was starting to look like I would have to return to England as I had nearly spent all my money.
One day while I was on Facebook, I found a message asking if anyone needed a job. I replied straight away and got the job! I was so happy I could stay with my girlfriend in Japan.
Facebook saved my relationship and enabled me to stay in Japan. In January this year I got engaged to Satoko and we will marry in spring next year.