ASP.NET Site Maps

Question: Has anyone got experience creating SQL-based ASP.NET site-map providers?

I've got the default XML file web.sitemap working properly with my Menu and SiteMapPath controls, but I'll need a way for the users of my site to create and modify pages dynamically.
I need to tie page viewing permissions into the standard ASP.NET membership system as well.

Solution:  Here's my fix in BuildSiteMap():

SiteMapNode node = GetSiteMapNodeFromReader(reader);
string url = node.Url;
if (url.Contains(":"))
{
    string garbage = Guid.NewGuid().ToString();  // SiteMapNode needs unique URLs
    node.Url = "~/dummy_" + garbage + ".aspx";
    AddNode(node, _root);
    node.Url = url;
}
else
{
    AddNode(node, _root);
}

SQLDependency caching is cool, but if you don't want to make a trip to the DB everytime your menu loads (to check to see if the dependency has changed) and your menus don't change very often, then why not use HttpRuntime.Cache instead?

public override SiteMapNode RootNode
{
    get
    {
        SiteMapNode temp = (SiteMapNode)HttpRuntime.Cache["SomeKeyName"];
        if (temp == null)
        {
            temp = BuildSiteMap();
            HttpRuntime.Cache.Insert("SomeKeyName", temp, null, DateTime.Now.AddHours(1), Cache.NoSlidingExpiration);
        }
        return temp;
    }
}