IETester兼容win7啦，http://www.my-debugbar.com/wiki/IETester/HomePage

IETester is a free WebBrowser that allows you to have the rendering and javascript engines of IE8, IE7 IE 6 and IE5.5 on Windows 7, Vista and XP, as well as the installed IE in the same process.
New in v0.5 : IETester now working on Windows 7 !

This is an alpha release, so feel free to post comments/bugs on the IETester forum.
Requirement : Windows 7, Windows Vista or Windows XP with IE7 (Windows XP/IE6 config has some problems and IE8 instance do not work under XP without IE7)

Download IETester v0.3.5 (24MB)
(IETester v0.3.5 zipped intaller for people unable to download .exe files due to proxy limitations)