image caching in wp7

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C#

I am using below code direct bind all the data into the list including images

void ListPostComingsoon_Completed(object sender, ListPostComingsoonCompletedEventArgs e)
        {
            ComingSoonList.ItemsSource = e.Result;
           
        }

And the List<> structure is something like below

select new post
                  {

                      postid = (int)r.postid,
                      userid = (int)r.userid,
                      NofLikeString = r.NofLike.ToString() + " Likes",
                      title = r.title,
                      startdate = r.startdate.ToString(),
                      enddate = r.enddate.ToString(),
                      image =   "http://localhost:6848/photo/" + r.image

                  }).ToList();

How can i achieve image caching(the image show separately once it's downloaded)?