Force.com Streaming API and Chrome Desktop Notifications
@abhinavguptas
How to set up PushTopics and get real-time chrome desktop notifications.

REST API Cheat Sheet: It’s Only Cheating if You’re Taking a Test
@forcedotcom
Force.com added a REST API cheat sheet to their library of cheat sheets.

Tip: Using Decimal Class with Strings in Apex
@abhinavguptas
Try storing your queried number field as a specific Type(Decimal) in a local variable, which will save you from any accidental code API version upgrade from breaking the existing code.

Sinatra, Force.com and Heroku- In Perfect Harmony
@metadaddy
A cookbook recipe that shows how to call the REST API from a Ruby Sinatra app.

Advanced Reporting and Dashboards in Salesforce: Google Visualization with Visualforce
@sfunearthed
Get started with Google Visualization API’s.