multiple django sites with apache & mod_wsgi

I want to host several sites with under the same server which uses Debian 5, say I have site1, site2 and site3, and assume my ip is 155.55.55.1:

site1: 155.55.55.1:80  , script at /opt/django/site1/
site2: 155.55.55.1:8080, script at /opt/django/site2/
site3: 155.55.55.1:8090, script at /opt/django/site3/

Here is my apache default:

<VirtualHost *:80>
    ServerName /
    ServerAlias  */
    DocumentRoot /opt/django/site1/
    LogLevel warn
    WSGIScriptAlias / /opt/django/site1/apache/django.wsgi
    Alias /media /opt/django/site1/media/statics
    Alias /admin_media  /home/myuser/Django-1.1/django/contrib/admin/media 
</VirtualHost>

<VirtualHost *:80>
    DocumentRoot "/usr/share/phpmyadmin"
    ServerName /phpmyadmin
    Alias /phpmyadmin /usr/share/phpmyadmin
    <Directory /usr/share/phpmyadmin>
        Options Indexes FollowSymLinks
        AllowOverride None
        Order Deny,Allow
        Allow from all
    </Directory>
</VirtualHost>

And here is my wsgi config for site1, at /opt/django/site1/apache/django.wsgi:

import os, sys
import django.core.handlers.wsgi

sys.path.append('/opt/django')
sys.path.append('/opt/django/site1')

os.environ['DJANGO_SETTINGS_MODULE'] = 'site1.settings'
application = django.core.handlers.wsgi.WSGIHandler()

How can I add site2 and site3, which are Django-based sites and will be served like site1?