Craigslist - Submitting posts too fast displays a message that “Craig can’t type them in this fast.”
Geeklist - Shows how long it would take for your password to be cracked in the sign up form.
Gigantt - When you estimate a task using free text you see a live preview of how the system is interpreting it.
/via Assaf Lavie
Gmail - Incompatible versions of Internet Explorer show a damaged envelope as the favicon.
/via Eric Hansz
British Gas - iPhone app has a button to turn on the camera light when submitting a meter reading.
/via Jaik Dean
Facebook - The prompt text in the “Update Status” field constantly changes on refresh.
/via Ahmed El-Agha
Amazon - Wish List will notify you that someone may have purchased an item on your wish list if you click-through to the item’s page.
YouTube - Clicking on the “Report” icon on YouTube stops the video if it’s currently playing.