The problem is that Radio Userland generates pages on the client-side, which are then FTP'ed up to the site, but you can't configure Radio Userland's file-naming conventions, so the site goes up as index.html, etc. So if you want to, say, integrate an ASP.NET Trackback mechanism, it's somewhat challenging, since IIS doesn't process files with .html extensions through ASP.NET. However, if you create a file called, say, index.aspx whose content is <!-- #include "index.html" -->, your .html file gets processed via the handler designated for the .aspx file extension. That's halfway there.

Unfortunately, Radio Userland uses ASP-like <%  tag %> tags, and so you can't just write an ASP.NET page and make it your Radio Userland template (as Radio Userland will attempt to interpret the ASP.NET tags, get confused, and generate static error messages where you desire server-side ASP.NET tags). However, you can use SSI's once again: by placing your ASP.NET code in separate server-side files and including code along the lines of <!-- #include file="myaspcomponent.ascx" --> in your Radio Userland template....

Well, you can do stuff like add 2 and 2 together. After that, it's a small step to a Trackback mechanism. Well, maybe not a small step, but the route seems clear.