Africa has the fastest-growing cell phone market in the world. We want you to tell us why. How has your mobile changed your life?

In South Africa, mobiles outnumber fixed lines by eight to one. Kenyans own more than 15 million handsets, while in Nigeria, the cell phone has "leapfrogged" the PC as the easiest way to surf the net.

SMS texts have been used to send malaria warnings, raise awareness of HIV/Aids, and even to report post election violence. In rural communities, cell phones are a lifeline for traders and farmers, helping them get better prices and save on huge journeys.

To coincide with this week's Mobile World Congress, the largest event of its kind, we want you to tell us about your mobile.