In My example I am writing Meta contents of my page from a utility class file.

Lets say my following method is in utility.cs file

// method that will write meta tags for keyword and description.

 public static void WriteMetaTags(Control ctrl, string keyword, string desc)

    {



        Page pge = (Page)ctrl;



        HtmlMeta mKey = new HtmlMeta();

        mKey.Name = "keyword";

        mKey.Content = key;

        pge.Header.Controls.Add(mKey);



        HtmlMeta mDesc = new HtmlMeta();

        mDesc.Name = "description";

        mDesc.Content = desc;

        pge.Header.Controls.Add(mDesc);



    }

I need to call this method from my .aspx page like this.
utility.WriteMetaTags(this, keyword, desc) and its done.

You can also call this method from a user control like
utility.WriteMetaTags(this.parent, keyword, desc)

Enjoy!!!