Community site and google optimization

Hi guys,

Two of my friends and myself have developped a cool project which will be done like a week, and I'd like it to go viral.

Its caracteristics are:
- It is a unifying project,
- It is fun and addictive,
- It just needs a boost and then it will take care of itself.

I'm actually finishing the coding of this site.
Problem is, how do you make optimization when the content is posted by the public?

People posting their stories, people voting... You get the point.
That's why I need to know how to optimize this site, knowing I have little control of the actual content.

Help welcome!

I think it's better if you could grouping the public access. Say users by interest category. It should optimize the contents for SEO to each category.

Don't forget to use 'tag cloud' block to direct SE spiders.

After completing website try to promote and make it familiar with search engines. Do exchange links with relevant websites, social bookmarking, add it in signature in forums.