Todd @ daishar.com just released Greasemonkey for Internet Explorer:
Lately, I’ve been working on a side project to bring the Greasemonkey concept of user scripts to Internet Explorer. Thus, GreasemonkIE. It’s still in a very early state, and I haven’t had a chance to get in all of the functionality that I’d like. However, I feel that it’s far enough along that I can put out there for others to use. You can download it here. It’s packaged as a Windows Installer. You’ll need to restart IE after it’s installed (you may need to close IE before installation). There’s no gui interaction so once the progress dialog goes away, it’s done.
Let’s not forget, IE has a huge marketshare… (well, it’s slowly being hacked away by Firefox, but it’s still pretty darn big)
(via Ajaxian Blog)