I bit the bullet and installed IE 7 on my main development machine (Windows XP SP2). I had held back due to the fact that one of my main clients has an Intranet web application running under IE 5.5 / IE 6.0 and I need to develop against that as the benchmark standard. Thanks to the wonderful Multiple IE installer I quickly had IE 3.0, IE 4.01, IE 5.01, IE 5.5 and IE 6.0 all available for testing my ASP.NET application. The only tricky bit was getting Visual Studio 2003 to run the ASP.NET application ......