How do I get my mum to trust me?

I'm 12 and all my friends have boyfriends and mobile phones and get to do stuff and go places but my mum doesn't let me do anything. I probably wouldn't be allowed a boyfriend, I only have an emergency phone because I catch the buss, and I can't go places with friends because they all live like 20 minutes drive away. She won't even leave me at home with my 10 yr old brother for more than 10 minutes! How can I get her to trust me more?