If you haven't been over to zodiackillerciphers.com recently, you should head over and have a look. Dave's added some really good content, including a detailed look at the 408 solution and some thoughts on the lesser-known concerned citizen who anonymously sent a solution key for the 408 to police.
Dave's blog has so much interesting stuff, I've given up on commenting on all of it. Instead, I've added an RSS feed to his blog in my sidebar. It's replacing the #ZodiacKiller twitter feed (let's be honest, that wasn't providing a whole lot of value...). Hopefully, this RSS feed will encourage people to regularly check out zodiackillerciphers.com.