If any of you are on older systems with a large hosts file this can reduce RAM size a lot for you (same size for everyone, but modern machines won't see a difference.) The hosts file is loaded into RAM and read so this could potentially effect DNS loads and there should be no downsides (though you do have to do this manually - it takes a second. There could be issues with things like SpyBot S&D etc.) If you're using Windows 2000 you may not be able to use 0 and instead will need to use 0.0.0.0. MVPS Original Size: 601.7kB Replacing 127.0.0.1 with 0.0.0.0 reduces the size of the MVPS Hosts file to 572.9kB Replacing 127.0.0.1 with 0 reduces the size of the MVPS Hosts file to 486kB (~120kB less) You can also remove things like #[Tracking Cookie] and other #'d areas to save ~10kB. You can also attach multiple hosts to an IP Code: 0 admigo.ru data.admigo.ru apps.admission.net appcache.admission.net You can eliminate ~2/3rds of the 0s by stacking them on each line. Without a script to automate this it'll take ages though. Just thought it was interesting that you can cut it down to nearly 1/2 its size. I don't know what the maximum number of hosts to an IP you can do, but there's probably a fair amount of memory to be saved. I've fit as many as 8 hosts to one IP.