Widgets in Posts for repeated content?

Hi,

I have theme that allows me to use Posts to create a shopping cart. The Posts are the products and their info. All of these posts need to display some standard product info which is repeated on each post. If I was designing a static site I would use an include for this repeated info.

How do I do this in WordPress?

I figured if I could use the Text widget in the main content area I’d be able to display this info. And if I edit the info at a later date all the Posts would be updated.

Any plugins or hacks that will enable me to display this repeated info on each post?

Thanks in advance