While reading up on gethostbyaddr on PHP.net, I saw a nice idea for using fsockopen to connect over UDP port 53 to any Public DNS server, like Google DNS 8.8.8.8, and sending the reverse addr lookup in oh about 100 bytes, then getting the response in oh about 150 bytes! All in less than a second. This is how/why to read/write data directly to the wire! This would be extremely valuable for use in things like my online header tool because it's faster than any other method. As usual, I went a bit overboard optimizing it to be lean and fast.

PHP's fsockopen function lets you open an Internet or Unix domain socket connection for connecting to a resource, and is one of the most powerful functions available in the php language.

Just a very brief look at speeding up form submission by delegating the processing and bandwidth to your server, not your client.