<p>I don't want <code>PHP</code> errors to display /html, but I want them to display in <code>/html/beta/usercomponent</code>. Everything is set up so that errors do not display at all. How can I get errors to just show up in that one folder (and its subfolders)?</p>

I don't believe there's a simple answer to this
, but I'd certainly want to  be proven wrong.
edit: turns out this can be controlled from .htaccess files. Thanks people! :)
You can use error_reporting()
http://docs.php.net/manual/en/function.error-reporting.php
to switch the setting on a script by script basis, though. If you happen to have a single script which is included every time at /html/beta/usercomponent, this will do the trick.