--- Facebook has blocked the ability to use this plugin. I repeat: It no longer works. To boot: It cannot be fixed, as Facebook has prevented bulk sends. It was fun while it lasted (RIP, Dec 2009)---
Sick an tired of clicking several hundred times when you want to invite your friends to a Facebook event? Yeah, me too. So I wrote a Greasemonkey script that does it for you. And just to be thorough, I wrote a bookmarklet too (for you non-GM people.)
Just to be clear, this code is GPL licensed, so feel free to use it, but keep it open.