Photo by Cat O
Egypt Influence Network - A network graph of Twitter users that actually tells a story. I do wish there was more discussion of the method and data used to generate it though. We all need reproducibility and peer review to strengthen our arguments.
CKAN - the Data Hub - A rich curated collection of data sets and APIs, with hopes to become the CPAN for information.
Weatherspark - Very effective interactive presentation of weather data. I especially like the faded background to the temperature graph subtly showing the mean, min and max values over time.
Spreadsheet Scraper - Simple but nice Chrome extension for pulling tabular data from web pages. Increasingly the client side is the only place to access third-party information, as robots.txt and API terms-of-service become more and more restrictive.
NoSQL @ NetFlix - It's very helpful that Sid has done so much work explaining NetFlix's experiences porting applications to NoSQL. It's often hard to convince companies with existing traditional infrastructures that switching is an option worth considering, these sort of case studies really help.