Want a hosted drupal, Mediawiki, Moodle or Joomla site? A most cost-effective way to learn the potential of these applications is Siteground:
Web Hosting Services: All-inclusive website hosting package, Free blog and CMS, Free domain, top customer care. SiteGround – the best Web Space Hosting Provider
At 6 $/month, this is possibly the best way to go through the learning cycle of some of these tools.
These sites are excellent for testing tools, but they fall short since module extension and problem solving are not supported. Still, at a nominal cost per year, we have a testing ground. We just should not use it in production.