I just upgraded from 2003 to 2007. In 2003, when I clicked "file", "new".
A window opened up on the right hand side of the screen. I had the option to
start a new file from an existing file or to start a new file from a
template. When I choose from a template, a window opened with all my
templates and I would choose the one I wanted.

In 2007, when I click file , new, it just opens a new spreadsheet.

How can I get "file new" to bring up a list of or choice to use a template?

I have the same problem with file new in MS Word 2007 also.