Nice Tools on gwebtools.com. Not really much unique stuff, and not
really "Amazing tools to increase your Network and Website
performance", but still fast and with some nice ideas.
Personally i don't like totally anonymous sites like gwebtools without
any name on it - but the author might have his/her reasons.
Be sure to check out the hosts-on-ns-function. It supports only
.com/.net, but it's using the .com/.net-zonefiles and is therefore
much more complete than Serversniffs NS-Catalog at
http://serversniff.net/nscatalog when it comes to these two tlds.