Digg Tag website

Site will need to run exactly like [login to view URL] Users will be able to login and submit urls. Once user submits urls they can add a title to the post, tag it in a certian category. Each listing will allow others to rate the post and leave comments. Each url submitted once posted should populate an image from the the page the link is from on the post, all hosted from the destination websites Users will have the ability to post a url and set it to a time frame to last in the system. example 1 day, 3 days, 10 days, one month. Each user will have a image that will present their profile on posts they upload and when they leave comments on other posts. A rating system will be needed which will rank the posts in order from ratings. Users can only rate a post one time. Please review and definitely understand the way the site [login to view URL] works exactly as this is the main goal.