Britney Spears and Justin Timberlake
Timberlake and Spears were arguably the most "2000s" couple that there ever was. This picture was taken at the 2005 MTV Awards. where they both were nominated for single of the year. Neither walked away with the award, but the press got a ton of pictures of them together, and that's what really matters in the long run.
The Introduction of the Camera Phone
This, right here, is one of the earliest selfies that had ever been taken. At a showcase of the Finnish technology company Vodafone's newest products in Japan, this lady took the opportunity to take a picture of herself with one of the first camera phones on the market. This phone wasn't available until about two years after this photo was snapped.