One of my fellow MVPs raised the issue that with Office 2007 he was not able to insert an Excel File into a Word document as a file icon (You click on the icon and Excel is launched). That feature is still there, just not easy to find.
1. First copy the Excel file you want to embed using Ctrl+C
2. Click the arrow under the Paste Button and Choose "Paste Special"
3. Choose the Excel File Type and then click the "Insert as Icon" Checkbox.
4. Click OK and you are done..