How can mod_rewrite be used effectively in PHP for URL rewriting?

Mod_rewrite can be used effectively in PHP for URL rewriting by creating rules in a .htaccess file to redirect incoming requests to a specific PHP file, which can then parse the URL and determine the appropriate content to display. This allows for clean and user-friendly URLs while still maintaining the functionality and structure of the underlying PHP code.

```php
RewriteEngine On
RewriteRule ^blog/([a-zA-Z0-9-]+)$ blog.php?slug=$1 [L]
```

In this example, any request to /blog/some-article will be rewritten to blog.php with the slug parameter set to some-article. This allows for dynamic content retrieval based on the URL structure.