Throwing in my $0.02 on the issue of ad blocking (and getting even more 
off topic)...

Great solution
--------------
Use Squid + Dansguardian on another machine


Good solution
--------------
Use PAC file with a very simple "blackhole" proxy server.

PAC file: O'Reilly republished Sheryl Canter's article about PAC files 
at 
http://www.windowsdevcenter.com/pub/a/windows/2004/03/30/hosts.html?page=2
or detailed info 
http://www.sherylcanter.com/articles/oreilly_20040330_HostsPac.php

Windows proxy: Blackhole Proxy 
(http://s91363763.onlinehome.us/BlackHoleProxy/)
Unix proxy: Noproxy (http://www.schooner.com/~loverso/no-ads/noproxy)


If you are unable to use squid + dansguardian, I highly recommend PAC 
file over HOSTS file. Why?
 - Easier to maintain than HOSTS file
 - Use wildcards (*)
 - Block specific paths (not whole hosts)
 - Redirect to different ports
 - Smaller than HOSTS file (huge HOSTS file can cause problems for some)

z