JavaJones, yes i did some tests with a proxomitron filter that time pageloads, host file definitely improves surfing speed.
For all the broadband people with newer pc's, this really isn't as noticeable as it is to someone with say...a 33.6k dialup connection and a slower pc.
I can tell you from experience that a huge hosts file doesn't speed up page loading.
Your pc has to scan through that whole file with every connection your pc makes to see if the domain is listed in there, first. This takes extra time.
The more domains you have to connect to for ads on a page, the more it has to scan that hosts file, the longer it takes to fail to load the ads. (But it even makes loading pages without ads take longer since you still have to go through that hosts file first)
The more entries you have in the host file, the longer it takes to scan that file.
So the hosts file option can backfire and not give you speed and actually slow you down.
If you don't believe me, try it with an 18,000+ line hosts file on a 233mhz machine on 33.6k dialup and compare speeds with & without. You won't even need a stopwatch. That's how noticeable it is.