My treasure

Something I treasure which is significant for me is my cell phone.
My cell phone is very costly, because the new one costs $800. It has many functions, and it is similar to a little computer. I can install many programs like English dictionary, games and personal documents etc. I save many songs in it, so I can listen to music everywhere. The other important function is that it is a simple camera. When I go shopping it can help me to remember the prices of the many things that I want to buy. I can compare the same things on different shop's prices, so I can make a good decision.
It's very valuable and useable, but it's not the main reason that I treasure it. It's a gift from my student's parents. I taught their children for 4 years, and we have become good friends. It belonged to the mother before, but she gave it to me when she knew I wanted to go to Australia. When I use my cell phone I can remember many interesting things about my students and their parents. I don't feel lonely anytime.
I don't think how valuable it is by money. Something is the most sentimental value, because it's a part of my memory.