Why does WordPress keep stripping out my carefully created map mashup?

Now that you've learned how to create map mashups, adding them to your site should be a simple matter of copy-and-paste, right? Not so fast - there are a number of issues you may run into when trying to insert the map embed code provided by Google and other providers to your site. We'll cover a few of those here.

For now, we're just covering this problem as it affects WordPress, but we know it affects other content management systems as well. If you have tips or advice on solving this for Plone, Drupal, or another CMS,  leave us a comment!