According to Paul Thurrott:
“We complain when Microsoft restricts certain features and functionality to only the latest product versions, so this report should be seen as good news. Although Microsoft Internet Explorer (IE) 7.0 will include Phishing Filter, a feature that helps protect users from scam Web sites, Microsoft believed that the feature was important enough to make it available to IE 6.0 users (via a plug-in for the MSN Search Toolbar) before IE 7.0’s release. (It’s due any day now, I’m told.) If you’re not into the MSN Search Toolbar but want antiphishing features, check out Netcraft Toolbar, which is what I use. There’s also a version for Mozilla Firefox.”
He likes NetCraft. I downloaded it once and disliked it almost immediately (maybe it’s gotten better). As I’m sure you’re tired of hearing, I’m a fan of Cloudmark’s antiphishing toolbar available here. I’ve also played with FraudEliminator and it’s quite good too.
Update: More info at News.com