Placing an ‘ | ‘ between page links …

Ok,

This may be a simple question, but I’m going to ask it anyway ..

I woulk like the pages wich are available to be listed with a ‘ | ‘ between them. like so : | About | Contact | Products | ETC | …

However, the ‘ | ‘ is not generated by wordpress automatically. How can I let it be generated betweem items ??

Many thanks,
-FOP-