Allows you to upload SVG files through the WordPress media uploader.

allow-svg-upload.php

<?php
/**
 * Plugin Name: Allow SVG Uploads
 * Plugin URI: http://wordpress.stackexchange.com/q/94003/19726
 * Description: Allows you to upload SVG files through the WordPress media uploader.
 * Author: Shea Bunge
 * Author URI: http://bungeshea.com
 * Version: 1.0
 */

function allow_svg_upload_mimes( $mimes ) {
	$mimes['svg'] = 'image/svg+xml';
	return $mimes;
}
add_filter( 'upload_mimes', 'allow_svg_upload_mimes' );