April 1 came and went with no significant effect from Conficker, but if you're still worried your computer may be infected with the widespread worm, the Conficker Eye Chart can diagnose it with ease.
The site is simple but brilliant. Conficker blocks access to some 100 security web sites, and the eye chart displays images from several of those sites. If your browser loads with the right configuration of dead images, then there's a very good chance you're computer's infected—meaning it's time you rid your self of the Conficker worm.
Conficker Eye Chart [Conficker Working Group]