Swap My City Pad
Swap your apartment with like-minded people in other cities throughout the world and keep the cost of a holiday down considerably.
http://www.swapmycitypad.com

Flowing Data
The ultimate site for data geeks, filled with maps, charts and diagrams which visualise data from a wide-range of topics like video games, sports, history, films and business.
http://flowingdata.com

One Photo Reviews
Scott reviews the latest film blockbusters not with flowing prose but with single shot profile pics of himself.
http://onephotoreviews.tumblr.com