I'm twenty - four years older than the author. Pretty crazy to compare our experiences...
5th grade (1/2): Everyone hangs out on Neopets, lots of people are excited about the GameCube. First time I ever heard of Google.
6th grade (2/3): Neopets is still popular (but popularity is starting to wane), people hang out on AIM, some start getting cell phones. lots of students carry their CD players to school and wear their headphones whenever they can.
7th grade (3/4): iPod Mini is the "hot device", more people have cell phones. everyone hangs out in AIM chat rooms.
8th grade (4/5): iPod Mini still in, most people now have cell phones. nerdy friends start playing World of Warcraft (some never stop, stealing to support the habit). Not many people know / care what MySpace is. A few people have gmail accounts.
9th grade (5/6): Everyone has MySpace. Most people are now using gmail. A few friends have blogs / Facebook. People torrent everything.
10th grade (6/7): MySpace is the hub of all social activity. Some start using Facebook once in a while. A few people create Twitter accounts. Only one or two rich kids have iPhones - they are teased mercilessly.