Type Key Authentication on PHP
Finally! There is a decent implementation for authentication using Type Key which you can download a copy of the Auth_Typekey which Daiji Hriata wrote. Looks way better than the PECL module called Auth_Typekey which I've been developing in my free time which is quite nasty c code seeing that I fortunately don't develop c code as part of my day job!
Also a resource called "Everything TypeKey" was setup by Jason Torrez from Drop Cash.
The links to download the code from auth-typekey.zip which is released under the PHP license :)
I'll make a PEAR package for Auth_Typekey later the weekend to make it easier to install than manually installing it in /usr/local/share/pear or whereever you have installed PEAR to.