We found the Netcraft toolbar played well alongside other secure browsing tools like McAfee SiteAdvisor (both free and paid) and Exploit Prevention Labs Linkscanner Pro, as well as with the native protection provided by Firefox 2 and Internet Explorer 7, even when we used all of them simultaneously. Should you ever want to uninstall the Netcraft toolbar, we had no trouble doing so.
Unlike Linkscanner Pro and SiteAdvisor--which both display their safety ratings over your current Google, Yahoo, or Live.com search result page--the Netcraft toolbar does not overlay its own ratings. And, despite an option to block cross-site scripting attacks, we still found a few defaced dangerous sites that Netcraft did not flag.
One defaced Web site, a Massachusetts-based restaurant Web site, was infected with a malicious Trojan. By viewing the source code of the page, we could see the hacker-added iframe script at the very bottom; in this case it called out to a site in Korea known to host malicious code. Another example was a sex site hosted in a foreign country; it hosted (deliberately or not) a malicious WMF file. With the Netcraft toolbar we were able to access both sites, and we were also asked whether we wanted to install the tainted WMF file. Similarly, neither SiteAdvisor nor the antiphishing protection within Firefox 2 or Internet Explorer 7 blocked our access to these sites. Only Linkscanner Pro flagged us, allowing us access to the sites only after stripping out the malicious content.
But Linkscanner Pro failed to identify most of the suspected phishing sites we visited; and that's where the Netcraft toolbar truly shines. Using 10 sites recently reported to a reputable, independent phish-tracking site, we found that the Netcraft toolbar identified and blocked access to all 10 sites, tied with the premium version of McAfee SiteAdvisor Plus; the next best tools were Linkscanner Pro and Firefox 2, each identifying or blocking access to 7 suspected phishing sites; they were followed by Internet Explorer 7 which blocked an abysmal 5 sites. The free edition of McAfee SiteAdvisor gave us inconsistent results over the five days we tested it, and was not ranked. In general, we found that IE 7 (at the bottom of our results pile) consistently failed to catch phishing sites less than one hour old, although IE 7 caught all phishing sites known for at least an hour or more. Most phishing sites are removed after their initial 72 hours.
The toolbar is free, so Netcraft does not provide live technical support. It does, however, provide a thorough glossary of terms, and a fairly complete FAQ, both accessible from the toolbar itself.
We've been using the Netcraft toolbar for our own defense against phishing and recommend it for that purpose. The price is right, and the protection is solid.