How big of a store front do you want?
You can create a single page by saving it as index.html. The index.html page will load before a index.php page will load.
You can even have a whole site where there's a button that says "Shop" or "See our products"
If you want to have something like a content management system, Joomla, phpnuke, etc, where you can create zen cart in a separate folder and have a button or link, or ads that lead to the store. only problem is that the customer may have to login twice.
If you choose wordpress and make it a blog with a store you can use the mod that ties Zen Cart and Wordpress together. Search the forum to find it.
John Patrick
A Zen Cart Advocate!