Visual Studio 2010 also includes some nice new “DataTip pinning” features that enable you to better see and track variable and expression values when in the debugger. 

Simply hover over a variable or expression within the debugger to expose its DataTip (which is a tooltip that displays its value)  – and then click the new “pin” button on it to make the DataTip always visible:

You can “pin” any number of DataTips you want onto the screen.  In addition to pinning top-level variables, you can also drill into the sub-properties on variables and pin them as well. 

Below I’ve “pinned” three variables: “category”, “Request.RawUrl” and “Request.LogonUserIdentity.Name”.  Note that these last two variable are sub-properties of the “Request” object.