This is what's in the registrations/register.php file around the area of blog creation details:
<?php /***** Blog Creation Details ******/ ?>
<div class="register-section" id="blog-details-section">
<h4><?php _e( 'Blog Details', 'buddypress' ) ?></h4>
<p><input type="checkbox" name="signup_with_blog" id="signup_with_blog" value="1"<?php if ( (int) bp_get_signup_with_blog_value() ) : ?> checked="checked"<?php endif; ?> /> <?php _e( 'Yes, I\'d like to create a new site', 'buddypress' ) ?></p>
<div id="blog-details"<?php if ( (int) bp_get_signup_with_blog_value() ) : ?>class="show"<?php endif; ?>>
<label for="signup_blog_url"><?php _e( 'Blog URL', 'buddypress' ) ?> <?php _e( '(required)', 'buddypress' ) ?></label>
<?php do_action( 'bp_signup_blog_url_errors' ) ?>
<?php if ( is_subdomain_install() ) : ?>
http:// <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>" /> .<?php echo preg_replace( '|^https?://(?:www\.)|', '', site_url() ) ?>
<?php else : ?>
<?php echo site_url() ?>/ <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>" />
<?php endif; ?>
<label for="signup_blog_title"><?php _e( 'Site Title', 'buddypress' ) ?> <?php _e( '(required)', 'buddypress' ) ?></label>
<?php do_action( 'bp_signup_blog_title_errors' ) ?>
<input type="text" name="signup_blog_title" id="signup_blog_title" value="<?php bp_signup_blog_title_value() ?>" />
<span class="label"><?php _e( 'I would like my site to appear in search engines, and in public listings around this network.', 'buddypress' ) ?>:</span>
<?php do_action( 'bp_signup_blog_privacy_errors' ) ?>
<label><input type="radio" name="signup_blog_privacy" id="signup_blog_privacy_public" value="public"<?php if ( 'public' == bp_get_signup_blog_privacy_value() || !bp_get_signup_blog_privacy_value() ) : ?> checked="checked"<?php endif; ?> /> <?php _e( 'Yes', 'buddypress' ) ?></label>
<label><input type="radio" name="signup_blog_privacy" id="signup_blog_privacy_private" value="private"<?php if ( 'private' == bp_get_signup_blog_privacy_value() ) : ?> checked="checked"<?php endif; ?> /> <?php _e( 'No', 'buddypress' ) ?></label>
</div>
</div><!-- #blog-details-section -->
I know the error must be in here somewhere, but I'm not sure exactly what to take out:
<?php if ( is_subdomain_install() ) : ?>
http:// <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>" /> .<?php echo preg_replace( '|^https?://(?:www\.)|', '', site_url() ) ?>
I definitely didn't alter THAT myself! haha...