"eye chart" to test for conficker - loads images from AV sites that conficker blocks
confickerworkinggroup.org
confickerworkinggroup.org
http://data2.kaspersky-labs.com:8080/special/KKiller_v3.4.1....
If you can't, the PC's infected.
I am much more reassured by this, then I would be with some website that said "You Are Safe". Presenting the user with the evidence that they are safe is much more reassuring than just saying "You Are Safe, trust us on this one, we know what we're talking about."