<p>How can I export a GridView's data to a Microsoft Excel 2007 file?</p>

<p>Also, does Microsoft Excel 2007 support html elements and tags?</p>

I have used
Aspose.Cells
to do this.  This component has a mechanism to programmatically create an Excel document from a GridView.  I usually have a LinkButton whose click event handler constructs the document and writes the data into the Response.