This is the type of plug-in that I wish I had last week :)  Mikhail has built an amazing plug-in for Visual Studio 2005 that enables you to spell check an ASP.NET page (in source view).  It has all the smarts to ignore the semantic markup and only check the content.  It leverages the Office 2003 spell-checker.  Definitey a great addition for anyone who is building content for the Web.  Details at: http://blogs.msdn.com/mikhailarkhipov/archive/2006/04/17/577471.aspx 

Let us know what you think!