I run Windows with a pretty hefty c:/windows/system32/drivers/etc/hosts file obtained from http://winhelp2002.mvps.org/hosts.htm. I update this file as regularly as I remember and layer it with appropriate add-ons in my modern web browser of choice, A/V, and firewall solutions.
Basically, I realize that a large (generally static) blacklisting hosts file is protection against KNOWN threats (and only those with names!), and very little help against unknown and emerging threats (or straight up IPs). I must admit that I have not checked to see if there are stats regarding the attack/infection rates of new threats vs. known threats though I would expect that old, known threats probably still outweigh new threats simply due to volume.
QUESTION: Is there any added value from running with a large (generally static) blacklisting hosts file when used with modern consumer-grade anti-virus and firewall solutions? Is it a redundant layer? I admit that A/V is generally a black box to me, so I'm not sure what kinds of signatures their engines scan for, and whether hostnames are part of those signatures.
Although this seems like a free extra security layer, there are "costs" with manually updating the file, and the fact that I turn off DNS caching to prevent the whole file from hanging the machine each time it reloads itself (which can be frequent). (I've migrated DNS caching to the router instead which doesn't help me when I use my laptop elsewhere.)