This isn't really related to your blog post, but I was perusing your source files on google code and noticed that there is a minor error on your http response list in:
system/functions/http.php -> Http::setStatus()
501 => "Method Not Allowed", is in fact http code 405, not 501.
While it's nice to have an exhaustive list of http response codes for reference, the large majority of these codes have no business being sent out by php... Specifically the 1xx codes, many of the 4xx codes, and most of the 5xx codes. Http 402, for instance is not even used in the current specification. You're never going to need to send out a 408, 413, 414, 504, 505, et cetera because those are all handled by apache for you... just my 2¢.
system/functions/http.php -> Http::setStatus()
501 => "Method Not Allowed", is in fact http code 405, not 501.
While it's nice to have an exhaustive list of http response codes for reference, the large majority of these codes have no business being sent out by php... Specifically the 1xx codes, many of the 4xx codes, and most of the 5xx codes. Http 402, for instance is not even used in the current specification. You're never going to need to send out a 408, 413, 414, 504, 505, et cetera because those are all handled by apache for you... just my 2¢.
The full spec can be found here:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html