Adding a Product at Opportunity Creation Time

Using the out of the box product management features (Admin/Content Management menus), is there a way to allow a user to select a product while they are creating an opportunity, not after they click save?  I find it strange that you can't do it for Products, but you can for all the customer objects.  In our particular project the users will only ever have a single product associated with an opportunity.

Thank you.

Mark