flashblockdetector – Project Hosting on Google Code
This is a pure-JavaScript library that detects whether Flash is blocked on the current page due to a Flash blocking extension. The current version can detect
* FlashBlock #1 for Chromium / Google Chrome (Windows/Mac/Linux)
* FlashBlock #2 for Chromium / Google Chrome (Windows/Mac/Linux)
* FlashBlock for Firefox (Windows/Mac/Linux)
* ClickToFlash 1.5.x (Mac/Safari only)