How to change sitecore shell favicon?

When I login into sitecore dektop or content editor or page editor there is default sitecore favicon. Is it possible to change this icon?

Solution

I created custom SheerUI control, and registered it in Web.config.

[ParseChildren(false)]
public class Favicon : Component
{
    public Favicon()
    {
        this.RenderAs = global::Sitecore.Web.UI.RenderAs.Literal;
    }

    protected override void DoRender(HtmlTextWriter output)
    {
        global::Sitecore.Context.ClientPage.Page.Header.Controls.Add(
            new Literal { Text = "<link rel=\"icon\" href=\"/faviconn.ico\" type=\"image/x-icon\" /><link rel=\"shortcut icon\" href=\"/faviconn.ico\" type=\"image/x-icon\" />" });
    }
}

Then I added tag:

<Favicon />

to \Website\sitecore\shell\Applications\Shell.xml.

I also added this two lines to /sitecore/login/default.aspx

<link rel="icon" href="/faviconn.ico" type="image/x-icon" />
<link rel="shortcut icon" href="/faviconn.ico" type="image/x-icon" />

I know this will not survive update, but It's good enough.