Wetpaint‘s September update is out, and it includes some really useful new features, and interface improvements. Also, congratulations to Wetpaint on reaching an impressive milestone: 25,000 wiki sites hosted! From the update:

• Add YouTube videos to your site
  You can now easily integrate YouTube videos into your Wetpaint site. Start by clicking the Video icon on the EasyEdit toolbar. Copy and paste in the YouTube video URL and – voilá – your Wetpaint site now has video. Check out our favorite YouTube video here.
• Search the entire Wetpaint network of sites
  Have you ever wondered if someone has created a site about the greatest soccer team on the planet – Celtic FC? Well, someone has. But you wouldn’t have been able to find it until now. Use the search box on the Wetpaint home page to search and explore sites about whatever topics interest you.
• Get notified when someone makes a comment
  When you leave a comment on any Wetpaint site, you now have an option to receive an email alert when someone responds to your comment. You’ll also get an email notification when someone leaves a comment on your profile page.
• An even faster editing experience
  If you’ve been using Wetpaint since the beginning, you’ll notice that the page editing experience is better and faster than ever. Perhaps improved performance isn’t as sexy a feature as YouTube videos, nor as obvious as the Wetpaint search functionality, but it will go a long way to making your Wetpaint experience even better.