Mkay, another plan for the coming weekend: a blog post. One that teaches a couple of tricks with which you can drive away a large percentage of the crawlers with no extra software, just your regular nginx/caddy/apache/whatever - and it only requires a few lines, nothing complicated, and it is extremely cheap to perform.
You can do 90% of what iocaine & Nam-Shub of Enki does, with any of the popular reverse proxies / http servers!
(iocaine will remain useful for the other 90% though. hehehe.)
Goo Truther 
@thufie Sadly, this will still require fiddling with nginx/caddy/apache/etc, so only helps if you control that. :(