With the next release of the PEAR Services_Trackback library comes this new post from Tobias Schlitt.

I finally managed to upload the next release of Services_Trackback (which is a generic class for sending and receiving trackbacks). The most important new feature for this version is integrated spam checking. Services_Trackback now implements a flexible API to add spam detection modules to a trackback using:

$trackback->createSpamCheck();
$trackback->addSpamCheck();
$trackback->removeSpamCheck();
$trackback->checkSpam();

[...] I beg everyone out there for feedback regarding the package (especially the developers of well-known weblog applications like Serendipity), it's facilities and it's API. Please comment on this blog entry! My wish would be to have Services_Trackback adopted by those applications to generate a single point of development for the trackback feature (which would be a benefit for all user, of course).

With so much blog spam out there, this package is deinitely a welcome addition to the mix. It enables you to use a few different types of spam checks, including: wordlists, regex, DNSBL (DNS blacklists), and SURBL ('Spam URI Realitme Blacklists'). For all of the details, see their PEAR page and download this handy little tool today!