There is a very neat plug-in that comes with Joomla 1.5 that enables you to embed any module inside any article.  

First, ensure that the "Content - Load Module" plugin is enabled by navigating to Extensions --> Plugin Manager from your Joomla! Administration site:

 Once this is enabled, you need to switch over to the Module Manager (Extensions --> Module Manager) and find the Module that you'd like to embed within the article.

From the edit mode of the Module, highlight the text that is in the Position field.  It looks like it's a dropdown menu only, but you can actually manually type in any entry you want here!

 Before:

After:

Now, you can manually choose the pages that you're going to have your module appear by highlighting the correct page on the Menu Assignment select box, or you can just choose to have it appear on all pages and it will still only show up in the articles where you embed the code (shown in the next step).

Save your changes and navigate over to the Content --> Article Manager page.

Edit or create the article that you'd like to place your Module in and switch to the HTML edit mode (not the What You See Is What You Get - WYSIWYG editing mode).

 Type in {loadposition CustomPosition} where CustomPosition is the text that you entered in the Module's Position field in the step above.

 Save your changes and navigate to the appropriate page on your site to view your handiwork in action.