Multiple instances of Excel (Multiple workbooks)

I wish to be able to VIEW two workbooks at the same time. Currently, I can
only view one workbook at a time, regardless of how many are open. I am using
Excel 2007.

In MS word 2007, when you open a document, and then open another document,
both documents are displayed on the desktop in seperate instances of Word.

In MS excel 2007, when I open a workbook, and then open another workbook,
both workbooks are displayed on the desktop in the same instance of excel.
This means I cannot view two workbooks simultaneously. I can switch between
the workbooks, but I want to be able to view multiple workbooks.