In my opinion...

The Birth of Social Media (Wikipedia, YouTube, Twitter, Facebook, MySpace etc)
Internet piracy
Harry Potter
Big Brother/Idol/The X Factor (interactive/live reality shows in general)
9/11 (and other prominent terrorist attacks) + War on Terror
Obama - the First Black President of the U.S.
Indian Ocean tsunami
SARS/Swine flu epidemics
Global Financial Crisis of late 00s
Pluto no longer a planet
Digital cameras/DVD/Blu-ray/HD TV/smartphones become the standard
LGBT rights/same-sex marriage introduced



WHAT ELSE?

for generic teen pop represented by certain talentless popstars

We used to call 90s fashion ugly 10 years ago...

yeah I just wanted be in the field of pop music, considering we are on atrl. And 00´s are definitely known for creating these stars with a perfect image but without any artistic input.

the way the internet changed the world, in 10 years, pretty incredible.. iPhone too

Obama

I think we knew less in general about popstars in preceding decades so it was hard to tell what was going on behind the scenes and who was involved in the creative process.

The internet boom.

9/11 terrorist attacks

Britney Spears

Birth of social media
Popularisation of smartphones
"War on Terrorism"
Global crisis of capitalism

Cingular

Britney Spears & Beyonce Knowles & Lady Gaga.

Apple. (iPads, iPods etc.)

iPhone.

Touchscreen Phones.

Beyoncé artist of the 00's decade you forgot the most important.

Jean Paul II died too.

the rise of Internet.