That's exactly what I've been doing to convince people to try to Firefox. After users come to me in frustration, complaining about Trojans, viruses, spyware, and other malware, I tell 'em about Firefox and how Firefox doesn't support things like ActiveX, so many forms of spyware and malware simply can't install. Ditto for Thunderbird.

Then when I install it and show them things like support for tabbed browsing, mouse gestures (via extensions), themeing, customizable toolbars, the download manager, etc., they are blown away and suddenly surprised they've never heard of it.

I think some ad campaigns are in order for the Mozilla Foundation, and ads that focus on Firefox's and Thunderbird's 'lack of support' for many common varieties of spyware and malware are exactly what's needed ...