AVG Linkscanner
@Mike.... perhaps time to get better broadband. I've got true a true 3Mbps service with a decent provider and use LinkScanner without any noticeable difference. Wouldn't use the Internet without using something like LinkScanner with all the drive by download infections out on the WWW! Scary to think the bad guys are infecting legitimate website to get their crapware out onto unsuspecting user's systems.
For example, here's one from earlier this year that saw LinkScanner Pro doing the needful:
http://www.theregister.co.uk/2008/02/07/forth_bridge_hack/
The bad guys have certainly got more proficient at hacking more and more websites since that incident.