I created a user control for BlogEngine.Net that will display the time it took to load the page.  This is pretty simple and straight forward to install:

1. Copy the files PageLoadTime.ascx and PageLoadTime.ascx.cs into your ~/User Controls folder

2. Add the following to the top of the site.master page:

<%@ Register Src="~/User controls/PageLoadTime.ascx" TagName="PageLoad" TagPrefix="pl" %>

3. Insert the following user control where ever you want the information displayed:

<pl:PageLoad ID="plPageLoad" runat="server" />

That's all you need to do. Now when the page loads you will see how long it took to load that page...

PageLoad.zip