This week, I installed TredoSoft's Multiple IE package (via friendly bit). It's an installer for Internet Explorer standalone versions 3, 4.01, 5.01, 5.5 and 6. It's based on evolt's standalone versions, but packed up in a nice installer. It even fixes some problems with cookies and conditional comments.
Check it out, it's a great package to have installed, and makes it a lot easier and cleaner to get all the old IEs running on your system. (You're all testing your web sites in IE 3, aren't you???)