There's been a lot of questions asked on the forums about how to embed videos or modify the built-in kses.php file, so I gathered the best responses and put it into a plugin for all to use. Just copy the plugin into the mu-plugins folder and your bloggers will be able to post YouTube, Google, and Flickr videos. If you look at the source code of the plugin you'll see how easy it is to add additional tags so that you could modify it to allow iframes, forms or whatever else you want. My usual disclaimer applies - I'm not a developer, I just hack these plugins together based on info I collect, feel free to modify and share. Thanks to donncha and taiwanese for their help on the forums - it was their code and ideas that contributed to this plugin.