Here's a bit of LINQ to XML VB.NET code that will get posts from your blog that have recent Disqus comments. I use it for the 'most popular pages' box on this website.
The code gets posts with comments from the Disqus RSS feed, groups them by post and selects the top eight. Use the StripOutURL function if you want to show just the basic URL for the post without the #comment tag that gives a direct link to the latest comment. The code also replaces the 'Re: ' that Disqus add to the title of the page in the RSS feed.
Function GetPostsWithComments() As String
Dim myIDAPI As New XDocument
myIDAPI = XDocument.Load("http://YOUR_DISQUS_SHORTCODE.disqus.com/latest.rss")
Dim Posts = (From Post In myIDAPI.Descendants("item") _
Select PostTitle = Post.Elements("title").Value, _
PostUrl = StripOutURL(Post.Elements("link").Value), _
PostCount = CInt(Post.Elements("item").Count) _
).GroupBy(Function(Poster) New String(Poster.PostTitle) _
).Take(8)
Dim sb As New StringBuilder
sb.Append("<ul>")
Dim myQuery = From c In Posts
For Each MyX In myQuery
sb.Append("<li><a href=""" & MyX.ElementAt(0).PostUrl & """ >" & Replace(MyX.ElementAt(0).PostTitle, "Re: ", "") & "</a></li>")
Next
sb.Append("</ul>")
Return sb.ToString
End Function
Private Function StripOutURL(ByVal s As String) As String
Dim str As String = ""
str = Left(s, s.IndexOf("#"))
Return str
End Function
