I was a freshman in high school when it was 2009.
I remember Twilight was popular as a book and the last Harry Potter book had released. I got into Lightning Theif and Aragon. I spent a lot of time in Barns and Noble because there where good books around that time.
I had a IPod Nano 5th generation in silver. They were really popular back then. My sister had purple, my best friend had apple green, and my other friend had red. We would listen to each others iPods on trips. We had cell phones at the time. The IPod just seemed like a cooler CD player with motion sensors so, of course, it had games on it and each color had a different one. Mine, was a maze with a ball, and you had to avoid the holes in the maze :)
Playing guitar hero..... All. Day. Long.
Eating Dippin' Dots ice cream at the mall, my favorite was cookie dough. My school always went to this mall and I always had to get it when we go to our music competitions.
Much like our parents from the 80's we had our own hairstyle that defined this decade.
It was long and straight with side bangs. Most of the blonds in my class dyed their hair brown because of Twilight.
Nobody wanted to look like a nerd. Everyone wore contacts at all cost.
Henley shirts, or a deep v sweater with lacy cami shirt was in. Watch High school musical if you want an idea.