Tredosoft have put together an version of IE 7 that installs in a standalone mode. This means that you can run it side-by-side with IE6 etc.
There is a small price to pay, not monetary though, some of the features just don't work like:
- Openning a new window and IE7's context menu.
- Bookmarks, RSS reader, and the search box. The search box works if you install IE7s using the installer. Alternatively, you can directly add search providers to the windows registry.
- Visiting pages that need HTTP authentication (username/password)
Check it out at http://tredosoft.com/IE7_standalone