Sachin Khosla

This plugin will allow you to remove the URL option from the comment box. This prevents automated bots to post spam links on your website. It helps your website retain the SEO Juice. 
This is a lightweight very simple plugin. No Javascript, ajax hack.
<h3>Usage</h3>
Simply activate the plugin and the URL input text box will not appear.

Disable / Hide Comment URL

Disable/Hide Comment URL lets you hide the URL/Website input field from the WordPress inbuilt comments block.

This plugin allows you to easily open and close your website and display a custom message or HTML page when closed.
<ul>
<li>Simple yes/no toggle to open/close your website.</li>
<li>Display your own closed.php within your theme.</li>
<li>Display your own custom HTML markup, pasted directly into the plugin settings.</li>
<li>Display a basic message informing your visitors that your website is closed.</li>
<li>Set paths which bypass the closed page entirely.</li>
<li>Set a bypass GET parameter which will allow anyone you give the URL to to browse the website as normal while the site is closed.</li>
<li>Automatically clears any caches for W3 Total Cache and WP Super Cache.</li>
</ul>

Website Open/Closed Toggle

This plugin allows you to easily open and close your website and display a custom message or HTML page when closed.

Disable / Hide Comment URL vs Website Open/Closed Toggle