I agree with Grant.

But if you are still inclined to develop the system, you can use SQL Profiler to Capture certain Queries based on events and conditions. Read more SQL Internals, Read more about building Graphsv(if your tool does not show me those beautiful graphs, i ain't gonna buy it) and build a better tool, that is not a resource hog, and do not test this against a prod server. 🙂