Well, I think for Americans it will be remembered as the decade that the majority of us showed our collective middle finger to the rest of the world and needed to spend the next several years rebuilding relationships.
It also marks the moment where we joined the rest of the world as victims of terrorism.
There are points where the musical mainstream seemed to be going in a good direction, but then it would just return us to 1999: Nu Metal, bad hip-hop about bitches and bling and the number of toilets the rapper possessed, lots of lip synching/rap synching, and some of the worst electronic music ever. Then again, it could be seen as the decade where indie stopped being indie.
Tech, definitely. Robotics in medicine, the beginnings of stem cell research, and useless cell phone apps.
Edit: And the greatest wealth of good TV ever. Concurrently, also the greatest wealth of absolute shit TV. But at least we had choices.