This is a great little article which I've used as the basis for a report linking information from a Project Management database (Planned Start Date, End Date, Estimated Effort) with a Time Sheet database (Actual Start Date, Actual Effort). Fundamentally the report is the same as the example except I've coded so the gantt bars are coloured depending on a couple of (self explanatory) factors:

On the Data tab for the Completed value:

=IIf(Fields!ActualEffort.Value > Fields!EstimatedEffort.Value, "Red", "YellowGreen")

On the Data tab for the Remaining value:

=IIf(Fields!EndDate.Value < Parameters!CurrentDate.Value, "Tomato","Gainsboro")

I've also added an action to all of the Data values to link to the project management application. The key value passed (Fields!ProjectKey.Value) is from the same dataset supporting the chart:

="javascrpt:void(window.open(" & Chr(34) & "http://www.abc.com/project/ProjectManagerUpdate.asp?key=" & Fields!ProjectKey.Value & Chr(34) & "))"

The brownie points are already accumulating - so thanks very much!