Hacker News on 4 September 2009

• How a software engineer invented a breakthrough medical device
• XSS Twitter in minutes; Why you shouldn't store important data with 37signals
• Get Less Done: Stop Being Productive and Enjoy Yourself
• Joe Stump: Why I switched from PHP to Python
• Inventing Demand
• Snakes on the Web
• Smule: I am T-Pain
• A Javascript date library
• Ask HN: 3 Ideas (with slides) for YC W10 - What do you think?
• Spreadsheet of every TED talk as of 9/2/2009