The latest release of Gallery (2.3) now has Akismet support built in. Thanks to Chris for letting us know.
Kevin at BIGACE CMS has developed a commenting extension which uses Akismet.
And lastly but by no means least the latest version of vBulletin blog also has Akismet support by default.
Akismet 
Regular vBulletin has it built in as well! 😀
Now Akismet is getting popular day by day.
And yes it deserves it.
No way out, huh? 🙂
Is Akismet responsible for a site being permanently blocked from all blogs or site on the internet?