Obama’s coming in as the US President was indeed a great event. But such was the interest in his swearing in that web sites were gearing up for more traffic. What happened was amazing though – the web traffic based on the search queries fired on Google shows that the world almost stopped!
Not only this, people also weren’t uploading pictures on Flickr  nor listening to their favorites songs on Last.fm Although many sites offered streaming video – who might have seen a spike – many normal attention hogs had more humble time during those few minutes! 
Just goes to show what one man – unknown 4 years back – could do to the entire technology world!
1. Search findings from the U.S. Presidential inauguration
2. Stop Flickring and Pay Attention: The Obama Curve
3. The Obama Curve: What an Inauguration does to your traffic – Web Requests
4. Web Sites Scale Up for Inauguration Traffic