Google Chrome Frame

Ok, this just looks fun:
http://blog.chromium.org/2009/09/introducing-google-chrome-frame.html

Allow your IE users to experience HTML 5 and faster Javascript rendering, by running your IE users inside Webkit via a Google Chrome Frame.

Prompt your IE users to install Google Code Frame plugin, then add a single meta tag to your pages, and... hello Chrome inside IE.

I don't know how "real world useful" it will be, because the people running IE 6 are probably not people that can or will install something like Google Chrome Frame.

But the idea is freaking cool. A little devilish, but very, very cool.

I'll have to check this one out a bit further.